├── .vscode
    └── settings.json
├── GFG TCS Sheet
    ├── 01]. Problems on Array
    │   ├── 08_Reverse_an_array_or_string.cpp
    │   ├── 09_Mean_Median_Mode_of_an_unsorted_array.cpp
    │   ├── 10_Smallest_and_Second_smallest_element_in_the_array.cpp
    │   ├── 11_Largest_Element_in_an_array.cpp
    │   ├── 12_Second_largest_element_in_an_array.cpp
    │   ├── 14_Program_for_addition_of_two_matrices.cpp
    │   ├── 16_Sum_of_elements_of_in_a_given_array.cpp
    │   ├── 17_Remove_duplicate_elements_from_sorted_Array.cpp
    │   ├── 21_Average_of_an_array.cpp
    │   ├── 23_Find_duplicates_in_array_in_O(n)_time.cpp
    │   └── README.md
    ├── 02]. Problems on String
    │   ├── !01_Count_vowels_consonents_digits_and_special_characters_in_a_string.cpp
    │   ├── 02_Given_string_is_palindrome_or_not.cpp
    │   ├── 03_ASCII_value_of_a_Character.cpp
    │   ├── 04_Remove_vowels_from_a_string.cpp
    │   ├── 05_Remove_spaces_from_a_given_string.cpp
    │   ├── 14_Strings_are_anagram_of_each_other.cpp
    │   ├── 15_Sort_string_of_characters.cpp
    │   └── README.md
    ├── 03]. Problems on Number Series
    │   ├── 01_Armstrong_numbers.cpp
    │   ├── 05_Replace_all_o's_with_5.cpp
    │   ├── 06_Number_is_positive_negative_odd_even_zero.cpp
    │   ├── 07_Harshad_Number.cpp
    │   ├── 12_Reverse_digits_of_a_number.cpp
    │   ├── 14_Sum_of_digits_of_number.cpp
    │   ├── 19_Perfect_number.cpp
    │   ├── 20_Palindrome_in_a_given_range.cpp
    │   ├── 22_Abundant_Number.cpp
    │   ├── 23_Sum_of_first_N_natural_numbers.cpp
    │   ├── 24_Sum_of_natural_numbers_in_range_L_to_R.cpp
    │   ├── 29_Check_if_a_number_is_palondrome_or_not.cpp
    │   ├── 30_Largest_and_smallest_digit_of_a_Number.cpp
    │   ├── 34_Area_of_Circle_Reclangle_and_Right_angled_Trinagle.cpp
    │   └── README.md
    ├── 04]. Problems on Conversions
    │   └── README.md
    ├── 05]. Sorting Algorithms
    │   ├── 01_Bubble_Sort.cpp
    │   ├── 03_Insertion_sort.cpp
    │   └── README.md
    └── README.md
├── README.md
└── Striver TCS Sheet
    ├── 01]. Arrays
        ├── 01_Find_the_smallest_number_in_an_array.cpp
        ├── 02_Find_the_Largest_element_in_an_array.cpp
        ├── 03_Find_Second_Smallest_and_Second_Largest_Element_in_an_array.cpp
        ├── 04_Reverse_a_given_Array.cpp
        ├── 05_Count_frequency_of_each_element_in_the_array.cpp
        ├── 06_Rearrange_array_in_increasing_decreasing_order.cpp
        ├── 07_Calculate_Sum_of_the_Elements_of_the_Array.cpp
        ├── 09_Average_of_all_the_elements_in_the_array.cpp
        ├── 10_Find_Median_of_the_given_Array.cpp
        ├── 11_Remove_Duplicates_in-place_from_Sorted_Array.cpp
        ├── 12_Remove_duplicates_from_unsorted_array.cpp
        ├── 13_Adding_Element_in_an_Array.cpp
        ├── 14_Find_all_repeating_elements_in_an_array.cpp
        ├── 15_Find_all_the_non_repeating_elements_in_an_array.cpp
        ├── 17_Maximum_Product_Subarray_in_an_Array.cpp
        ├── 18_Replace_elements_by_its_rank_in_the_array.cpp
        ├── 19_Sort_Elements_of_an_Array_by_Frequency.cpp
        ├── 24_Search_an_Element_in_an_Array.cpp
        ├── README.md
        └── tempCodeRunnerFile.cpp
    ├── 02]. Problems_on_Numbers
        ├── 01_Check_if_a_number_is_Palindrome_or_Not.cpp
        ├── 03_Check_if_a_number_is_prime_or_not.cpp
        ├── 04_Prime_Numbers_in_a_given_range.cpp
        ├── 06_Check_whether_a_number_is_Perfect_Number_or_not.cpp
        ├── 07_Check_whether_a_given_number_is_even_or_odd.cpp
        ├── 08_Check_whether_a_number_is_positive_or_negative.cpp
        ├── 09_Sum_of_first_N_Natural_Numbers.cpp
        ├── 12_Greatest_of_two_numbers.cpp
        ├── 13_Greatest_of_three_numbers.cpp
        ├── 15_Reverse_digits_of_a_number.cpp
        ├── 16_Maximum_and_Minimum_digit_in_a_number.cpp
        ├── 17_Print_Fibonacci_Series_up_to_Nth_term.cpp
        ├── 18_Factorial_of_a_Number.cpp
        ├── 19_Calculate_the_Power_of_a_Number.cpp
        ├── 21_Print_all_Prime_Factors_of_the_given_number.cpp
        ├── 22_Check_if_a_number_is_a_Strong_Number_or_not.cpp
        ├── 26_Check_if_the_given_number_is_Harsha_Or_Niven_Number.cpp
        ├── 27_Check_if_the_number_is_an_abundant_number_or_not.cpp
        ├── 28_Sum_Of_Digits_of_A_Number.cpp
        ├── 29_Find_the_sum_of_numbers_in_the_given_range.cpp
        ├── 32_Replace_all_the_0s_with_1_in_a_given_integer.cpp
        ├── 33_Express_given_number_as_Sum_of_Two_Prime_Numbers.cpp
        ├── 34_Calculate_the_Area_of_the_Circle.cpp
        ├── README.md
        └── tempCodeRunnerFile.cpp
    ├── 03]. Problems_on_Number_System
        ├── 01_Convert_Binary_to_Decimal.cpp
        ├── 02_Binary_Number_to_Octal_Number.cpp
        ├── 03_Convert_Decimal_to_Binary_Number.cpp
        ├── 04_Decimal_to_octal_conversion.cpp
        ├── 05_Octal_to_Binary_numbers.cpp
        ├── 06_Octal_to_decimal.cpp
        ├── README.md
        └── tempCodeRunnerFile.cpp
    ├── 04]. Problems_on_Sorting
        ├── 01_Bubble_Sort.cpp
        ├── 02_Insertion_Sort.cpp
        ├── 03_Selection_Sort.cpp
        ├── 04_Quick_Sort.cpp
        ├── 05_Merge_Sort.cpp
        └── README.md
    ├── 05]. Problems_on_String
        ├── 01_Check_if_the_given_String_is_Palindrome_or_not.cpp
        ├── 02_Count_number_of_vowels_and_consonants_and_spaces_in_String.cpp
        ├── 03_Find_the_ASCII_value_of_a_character.cpp
        ├── 04_Remove_all_vowels_from_the_String.cpp
        ├── 05_Remove_Spaces_from_a_String.cpp
        ├── 06_Remove_characters_from_a_string_except_alphabets.cpp
        ├── 07_Reverse_a_String.cpp
        ├── 08_Remove_brackets_from_an_algebraic_expression.cpp
        ├── 10_Capitalize_first_and_last_character_of_each_word_of_a_string.cpp
        ├── 11_Calculate_Frequency_of_characters_in_a_String.cpp
        ├── 12_Find_Non_repeating_characters_of_a_String.cpp
        ├── 13_Check_if_two_Strings_are_anagrams_of_each_other.cpp
        ├── 16_Maximum_occurring_character_in_a_string.cpp
        ├── 17_Remove_All_Duplicates_from_a_String.cpp
        ├── 18_Print_all_the_duplicates_in_the_string.cpp
        ├── 19_Remove_Characters_from_first_String_present_in_the_Second_String.cpp
        ├── 20_Change_every_letter_with_next_lexicographic_alphabet.cpp
        ├── 22_Write_a_program_to_sort_characters_in_a_string.cpp
        ├── 23_Count_the_number_of_words_in_a_given_string.cpp
        ├── 25_Change_case_of_each_character_in_a_string.cpp
        ├── 26_Concatenate_one_string_to_another.cpp
        └── README.md
    └── README.md


/.vscode/settings.json:
--------------------------------------------------------------------------------
1 | {
2 |     "files.associations": {
3 |         "unordered_map": "cpp",
4 |         "ostream": "cpp"
5 |     }
6 | }


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/GFG TCS Sheet/01]. Problems on Array/08_Reverse_an_array_or_string.cpp:
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 1 | //User function Template for C++
 2 | 
 3 | string reverseWord(string str){
 4 |     int l=0; 
 5 |     int r=str.length()-1;
 6 |     
 7 |     while(l<r){
 8 |         int temp = str[l];
 9 |         str[l]=str[r];
10 |         str[r]=temp;
11 |         l++;
12 |         r--;
13 |     }
14 |     return str;
15 |   //Your code here
16 | }


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/GFG TCS Sheet/01]. Problems on Array/09_Mean_Median_Mode_of_an_unsorted_array.cpp:
--------------------------------------------------------------------------------
 1 | /* 
 2 | Given an unsorted array a[] of size N, the task is to find its mean and median. 
 3 | 
 4 | Mean of an array = (sum of all elements) / (number of elements)
 5 | 
 6 | The median of a sorted array of size N is defined as the middle element when N is odd and average of middle two elements when N is even. Since the array is not sorted here, we sort the array first, then apply above formula.
 7 | 
 8 | Examples: 
 9 | 
10 | Input: a[] = {1, 3, 4, 2, 6, 5, 8, 7}
11 | Output: Mean = 4.5, Median = 4.5
12 | Explanation: Sum of the elements is 1 + 3 + 4 + 2 + 6 + 5 + 8 + 7 = 36, Mean = 36/8 = 4.5
13 | Since number of elements are even, median is average of 4th and 5th largest elements, which means Median = (4 + 5)/2 = 4.5
14 | 
15 | Input: a[] = {4, 4, 4, 4, 4}
16 | Output: Mean = 4, Median = 4 
17 | */
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | double getMean(double a[], int n){
23 |     double sum=0;
24 |     for(int i=0; i<n; i++){
25 |         sum+=a[i];
26 |     }
27 |     return sum/n;
28 | }
29 | 
30 | double getMedian(double a[], int n){
31 |     if(n%2==0){
32 |         return (a[n/2]+a[(n/2)+1])/2;
33 |     }
34 |     else{
35 |         return a[(n/2)+1];
36 |     }
37 | }
38 | 
39 | 
40 | void getMeanMedian(double a[], int n){
41 |     sort(a, a+n);
42 |     cout<<getMean(a, n)<<" "<<getMedian(a, n)<<endl;
43 | }
44 | 
45 | int main()
46 | {
47 |     double a[] = {1, 3, 4, 2, 6, 5, 8, 7};
48 |     getMeanMedian(a, 8);
49 | 
50 |     double a2[] = {4, 4, 4, 4, 4};
51 |     getMeanMedian(a2, 4);
52 |     return 0;
53 | }
54 | 


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/GFG TCS Sheet/01]. Problems on Array/10_Smallest_and_Second_smallest_element_in_the_array.cpp:
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 1 | /*
 2 | Given an array of integers, your task is to find the smallest and second smallest element in the array. If smallest and second smallest do not exist, print -1.
 3 | 
 4 | Example 1:
 5 | 
 6 | Input :
 7 | 5
 8 | 2 4 3 5 6
 9 | Output :
10 | 2 3 
11 | Explanation: 
12 | 2 and 3 are respectively the smallest 
13 | and second smallest elements in the array.
14 | 
15 | Example 2:
16 | 
17 | Input :
18 | 6
19 | 1 2 1 3 6 7
20 | Output :
21 | 1 2 
22 | Explanation: 
23 | 1 and 2 are respectively the smallest 
24 | and second smallest elements in the array.
25 | */ 
26 | 
27 | vector<int> minAnd2ndMin(int a[], int n) {
28 |     int s1=INT_MAX, s2=INT_MAX;
29 |     set<int>s(a, a+n);
30 |     if(s.size()<=1){
31 |         return {-1};
32 |     }
33 |     
34 |     
35 |     for(int i=0; i<n; i++){
36 |         s1=min(s1, a[i]);
37 |     }
38 |     
39 |     for(int i=0; i<n; i++){
40 |         if(a[i]!=s1){
41 |             s2=min(s2, a[i]);
42 |         }
43 |     }
44 |     
45 |     return {s1, s2};
46 | } 


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/GFG TCS Sheet/01]. Problems on Array/11_Largest_Element_in_an_array.cpp:
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 1 | /*
 2 | Given an array arr[] of size N, the task is to find the largest element in the given array. 
 3 | 
 4 | Examples: 
 5 | 
 6 | Input: arr[] = {10, 20, 4}
 7 | Output: 20
 8 | Explanation: Among 10, 20 and 4, 20 is the largest. 
 9 | 
10 | Input : arr[] = {20, 10, 20, 4, 100}
11 | Output : 100
12 | 
13 | */ 
14 | 
15 | #include<iostream>
16 | #include<limits.h>
17 | using namespace std;
18 | 
19 | int getLargest(int arr[], int n){
20 |     int lar=INT_MIN;
21 |     for(int i=0; i<n; i++){
22 |         lar=max(lar, arr[i]);
23 |     }
24 |     return lar;
25 | }
26 | 
27 | int main()
28 | {
29 |     int arr[] = {10, 20, 4};
30 |     cout<<getLargest(arr, 3)<<endl;
31 | 
32 |     int arr2[] = {20, 10, 20, 4, 100};
33 |     cout<<getLargest(arr2, 5)<<endl;
34 |     return 0;
35 | }
36 | 


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/GFG TCS Sheet/01]. Problems on Array/12_Second_largest_element_in_an_array.cpp:
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 1 | /*
 2 | Given an array of integers, our task is to write a program that efficiently finds the second-largest element present in the array. 
 3 | 
 4 | Example:
 5 | 
 6 | Input: arr[] = {12, 35, 1, 10, 34, 1}
 7 | Output: The second largest element is 34.
 8 | Explanation: The largest element of the 
 9 | array is 35 and the second 
10 | largest element is 34
11 | 
12 | Input: arr[] = {10, 5, 10}
13 | Output: The second largest element is 5.
14 | Explanation: The largest element of 
15 | the array is 10 and the second 
16 | largest element is 5
17 | 
18 | Input: arr[] = {10, 10, 10}
19 | Output: The second largest does not exist.
20 | Explanation: Largest element of the array 
21 | is 10 there is no second largest element
22 |  */ 
23 | 
24 | #include<bits/stdc++.h>
25 | using namespace std;
26 | 
27 | int getSecondLargest(int arr[], int n){
28 |     set<int>s(arr, arr+n);
29 |     if(s.size()==1){
30 |         return -1;
31 |     }
32 |     vector<int>v(s.begin(), s.end());
33 |     return v[s.size()-2];
34 | }
35 | 
36 | int main()
37 | {
38 |     int arr[]{12, 35, 1, 10, 34, 1};
39 |     cout<<getSecondLargest(arr, 6)<<endl;
40 | 
41 |     int arr1[]{10, 5, 10};
42 |     cout<<getSecondLargest(arr1, 3)<<endl;
43 | 
44 |     int arr2[]{10, 10, 10};
45 |     cout<<getSecondLargest(arr2, 3)<<endl;
46 | 
47 |     return 0;
48 | }
49 | 


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/GFG TCS Sheet/01]. Problems on Array/14_Program_for_addition_of_two_matrices.cpp:
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 1 | // Addition of two square matrices
 2 | 
 3 | //User function Template for C++
 4 | class Solution {
 5 | public:
 6 |     void Addition(vector<vector<int> >& matrixA, vector<vector<int>>&matrixB) {
 7 |         // Code here
 8 |         int m=matrixA.size();
 9 |         int n=matrixB.size();
10 |         
11 |         for(int i=0; i<m; i++){
12 |             for(int j=0; j<n; j++){
13 |                 matrixA[i][j]+=matrixB[i][j];
14 |             }
15 |         }
16 |     }
17 | };


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/GFG TCS Sheet/01]. Problems on Array/16_Sum_of_elements_of_in_a_given_array.cpp:
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 1 | //User function Template for C++
 2 | 
 3 | //Complete this function
 4 | 
 5 | int sumElement(int arr[],int n)
 6 | {
 7 |     //Your code here
 8 |     int sum = 0;
 9 |     for(int i = 0; i<n; i++)
10 |     {
11 |         sum += arr[i];
12 |     }
13 |     return sum;
14 | }
15 | 
16 | 
17 | 


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/GFG TCS Sheet/01]. Problems on Array/17_Remove_duplicate_elements_from_sorted_Array.cpp:
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 1 | // Remove duplicate elements from sorted Array
 2 | //User function template for C++
 3 | 
 4 | class Solution{
 5 | public:
 6 |     int remove_duplicate(int a[],int n){
 7 |         // code here
 8 |         set<int>s(a, a+n);
 9 |         vector<int>v(s.begin(), s.end());
10 |         for(int i=0; i<s.size(); i++){
11 |             a[i]=v[i];
12 |         }
13 |         return v.size();
14 |     }
15 | };


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/GFG TCS Sheet/01]. Problems on Array/21_Average_of_an_array.cpp:
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 1 | class Solution {
 2 |   public:
 3 |     int mean(int N , int A[]) {
 4 |         // code here
 5 |         double avg=0;
 6 |         double sum=0;
 7 |         for(int i=0; i<N; i++){
 8 |             sum+=A[i];
 9 |         }
10 |         avg=floor(sum/N);
11 |         return avg;
12 |     }
13 | };
14 | 
15 | 


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/GFG TCS Sheet/01]. Problems on Array/23_Find_duplicates_in_array_in_O(n)_time.cpp:
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 1 | class Solution{
 2 |   public:
 3 |     vector<int> duplicates(int arr[], int n) {
 4 |         // code here
 5 |         vector<int>v;
 6 |         set<int>s;
 7 |         unordered_map<int, int>mp;
 8 |         for(int i=0; i<n; i++){
 9 |             mp[arr[i]]++;
10 |         }
11 |         
12 |         for(auto x: mp){
13 |             if(x.second>1){
14 |                 v.push_back(x.first);
15 |             }
16 |         }
17 |         
18 |         if(v.size()==0){
19 |             v.push_back(-1);
20 |         }
21 |         for(auto x: v){
22 |             s.insert(x);
23 |         }
24 |         v.clear();
25 |         for(auto x: s){
26 |             v.push_back(x);
27 |         }
28 |         return v;
29 |     }
30 | };


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/GFG TCS Sheet/01]. Problems on Array/README.md:
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1 | # Problems on Array


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/GFG TCS Sheet/02]. Problems on String/!01_Count_vowels_consonents_digits_and_special_characters_in_a_string.cpp:
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 1 | /*
 2 | Given a string and the task is to count vowels, consonant, digits and special character in string. Special character also contains the white space.
 3 | Examples: 
 4 |  
 5 | 
 6 | Input : str = "geeks for geeks121"
 7 | Output : Vowels: 5
 8 |          Consonant: 8
 9 |          Digit: 3
10 |          Special Character: 2
11 | 
12 | Input : str = " A1 B@ d  adc"
13 | Output : Vowels: 2
14 |          Consonant: 4
15 |          Digit: 1
16 |          Special Character: 6
17 | */ 
18 | 
19 | #include<iostream>
20 | using namespace std;
21 | 
22 | void getCount(string s){
23 |     int count_vowels=0;
24 |     int count_consonents=0;
25 |     int count_digits=0;
26 | 
27 |     for(int i=0; i<s.length(); i++){
28 |         if('0' <=s[i] && s[i]>='9'){
29 |             count_digits++;
30 |         }
31 |         else if(s[i]=='a' || s[i]=='e' || s[i]=='i' || s[i]=='o' || s[i]=='u'){
32 |             count_vowels++;
33 |         }else
34 |         {
35 |             count_consonents++;        
36 |         }
37 |     }
38 |     cout<<"digits : "<<count_digits<<endl;
39 |     cout<<"Vowels: "<<count_vowels<<endl;
40 |     cout<<"Consonents: "<<count_consonents<<endl;
41 |     cout<<endl;
42 | }
43 | 
44 | int main(){
45 |     string s="geeks for Geeks121";
46 |     getCount(s);
47 |     return 0;
48 | }


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/GFG TCS Sheet/02]. Problems on String/02_Given_string_is_palindrome_or_not.cpp:
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 1 | //User function template for C++
 2 | class Solution{
 3 | public:	
 4 | 	
 5 | 	
 6 | 	int isPalindrome(string S)
 7 | 	{
 8 | 	    // Your code goes here
 9 | 	    int i=0; 
10 | 	    int j=S.length()-1;
11 | 	    while(i<j){
12 | 	        if(S[i]!=S[j])
13 | 	            return 0;
14 |     	    i++;
15 |     	    j--;
16 | 	    }
17 | 	    return 1;
18 | 	}
19 | 
20 | };


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/GFG TCS Sheet/02]. Problems on String/03_ASCII_value_of_a_Character.cpp:
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 1 | /*
 2 | Given a character, we need to print its ASCII value in C/C++/Java/Python. 
 3 | 
 4 | Examples :
 5 | 
 6 | Input : a 
 7 | Output : 97
 8 | 
 9 | Input : D
10 | Output : 68
11 | 
12 | 
13 | */ 
14 | 
15 | #include<iostream>
16 | using namespace std;
17 | 
18 | int get_ASCII_value(char c){
19 |     return c;
20 | }
21 | 
22 | int main(){
23 |     cout<<get_ASCII_value('a')<<endl;
24 |     return 0;
25 | }


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/GFG TCS Sheet/02]. Problems on String/04_Remove_vowels_from_a_string.cpp:
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 1 | //User function template for C++
 2 | class Solution{
 3 | public:	
 4 | 		
 5 | 	string removeVowels(string S) 
 6 | 	{
 7 | 	    // Your code goes here
 8 | 	    int n=S.length();
 9 | 	    string res="";
10 | 	    for(int i=0; i<n; i++){
11 | 	       if(S[i]!='a' && S[i]!='e' && S[i]!='i' && S[i]!='o' && S[i]!='u'){
12 | 	           res+=S[i];
13 | 	       }
14 | 	    }
15 | 	    return res;
16 | 	}
17 | };


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/GFG TCS Sheet/02]. Problems on String/05_Remove_spaces_from_a_given_string.cpp:
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 1 | class Solution
 2 | {
 3 |   public:
 4 |     string modify (string s)
 5 |     {
 6 |         //code here.
 7 |         string res="";
 8 |         int n=s.length();
 9 |         for(int i=0; i<n; i++){
10 |             if(s[i]!=' '){
11 |                 res+=s[i];
12 |             }
13 |         }
14 |         return res;
15 |     }
16 | };


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/GFG TCS Sheet/02]. Problems on String/14_Strings_are_anagram_of_each_other.cpp:
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 1 | class Solution
 2 | {
 3 |     public:
 4 |     //Function is to check whether two strings are anagram of each other or not.
 5 |     bool isAnagram(string a, string b){
 6 |         int m=a.length();
 7 |         int n=b.length();
 8 |         sort(a.begin(), a.end());
 9 |         sort(b.begin(), b.end());
10 |         if(a==b){
11 |             return true;
12 |         }
13 |         else{
14 |             return false;
15 |         }
16 |     }
17 | 
18 | };


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/GFG TCS Sheet/02]. Problems on String/15_Sort_string_of_characters.cpp:
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1 |     
2 | string sort(string s){
3 |     //complete the function here
4 |     sort(s.begin(), s.end());
5 |     return s;
6 | }


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/GFG TCS Sheet/02]. Problems on String/README.md:
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1 | # Problems on String


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/GFG TCS Sheet/03]. Problems on Number Series/01_Armstrong_numbers.cpp:
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 1 | // Armstrong Numbers
 2 | // User function Template for C++
 3 | class Solution {
 4 |   public:
 5 |     string armstrongNumber(int n){
 6 |         // code here
 7 |         int temp=n;
 8 |         int res=0;
 9 |         vector<int>v;
10 |         
11 |         while(temp>0){
12 |             v.push_back(temp%10);
13 |             temp/=10;
14 |         }
15 |         for(int i=0; i<v.size(); i++){
16 |             res+=(v[i]*v[i]*v[i]);
17 |         }
18 |         
19 |         if(n==res){
20 |             return "Yes";
21 |         }
22 |         else{
23 |             return "No";
24 |         }
25 |     }
26 | };


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/GFG TCS Sheet/03]. Problems on Number Series/05_Replace_all_o's_with_5.cpp:
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 1 | class Solution{
 2 |   public:
 3 |     /*you are required to complete this method*/
 4 |     int convertFive(int n)
 5 |     {
 6 |         int res=0;
 7 |         vector<int>v;
 8 |         while(n>0){
 9 |             v.push_back(n%10);
10 |             n/=10;
11 |         }
12 |         reverse(v.begin(), v.end());
13 |         for(int i=0; i<v.size(); i++){
14 |             if(v[i]==0){
15 |                 res=(res*10)+5;
16 |             }
17 |             else{
18 |                 res=(res*10)+v[i];
19 |             }
20 |         }
21 |         return res;
22 |     }
23 | };


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/GFG TCS Sheet/03]. Problems on Number Series/06_Number_is_positive_negative_odd_even_zero.cpp:
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 1 | /*
 2 | Given a number n, the task is to check whether the given number is positive, negative, odd, even, or zero.
 3 | input : num = -98;
 4 | */ 
 5 | 
 6 | 
 7 | #include<iostream>
 8 | using namespace std;
 9 | 
10 | // void getOddOrEven(int &num);
11 | // void checkNumber(int &num);
12 | void getOddEven(int &num){
13 |     if(num%2==0){
14 |         cout<<" Even "<<endl;
15 |     }else{
16 |         cout<<" Odd "<<endl;
17 |     }
18 | }
19 | 
20 | void checkNumber(int &num){
21 |     if(num>0){
22 |         cout<<" Positive ";
23 |     }else if(num<0){
24 |         cout<<" Negative ";
25 |     }
26 |     else{
27 |         cout<<" Zero ";
28 |     }
29 | }
30 | 
31 | int main()
32 | {
33 |     int num=-98;
34 |     checkNumber(num);
35 |     getOddEven(num);
36 |     return 0;
37 | }
38 | 
39 | 
40 | 


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/GFG TCS Sheet/03]. Problems on Number Series/07_Harshad_Number.cpp:
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 1 | /*
 2 | An integer number in base 10 which is divisible by the sum of its digits is said to be a Harshad Number. An n-Harshad number is an integer number divisible by the sum of its digit in base n.
 3 | Below are the first few Harshad Numbers represented in base 10:
 4 | 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 18, 20………
 5 | Given a number in base 10, our task is to check if it is a Harshad Number or not.
 6 | 
 7 | Examples : 
 8 | 
 9 | Input: 3
10 | Output: 3 is a Harshad Number
11 | 
12 | Input: 18
13 | Output: 18 is a Harshad Number
14 | 
15 | Input: 15
16 | Output: 15 is not a Harshad Number
17 | */ 
18 | 
19 | #include<iostream>
20 | using namespace std;
21 | 
22 | void isHarshadNumber(int n){
23 |     int temp=n;
24 |     int sum=0;
25 |     while(temp){
26 |         sum+=temp%10;
27 |         temp/=10;
28 |     }
29 |     if(n%sum==0){
30 |         cout<<"YES";
31 |     }
32 |     else {
33 |         cout<<"NO";
34 |     }
35 |     cout<<endl;
36 | }
37 | 
38 | int main(){
39 |     isHarshadNumber(3);
40 |     isHarshadNumber(18);
41 |     isHarshadNumber(15);
42 | 
43 |     return 0;
44 | }


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/GFG TCS Sheet/03]. Problems on Number Series/12_Reverse_digits_of_a_number.cpp:
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 1 | /*
 2 | Write a program to reverse the digits of an integer.
 3 | 
 4 | 
 5 | 
 6 | Examples :  
 7 | 
 8 | Input : num = 12345
 9 | Output: 54321
10 | 
11 | Input : num = 876
12 | Output: 678
13 | 
14 | */ 
15 | #include<iostream>
16 | using namespace std;
17 | 
18 | int getReverse(int num){
19 |     int res=0;
20 |     while(num>0){
21 |         res=(res*10)+num%10;
22 |         num/=10;
23 |     }
24 |     return res;
25 | }
26 | 
27 | int main()
28 | {
29 |     int num=12345;
30 |     cout<<getReverse(num)<<endl;
31 |     cout<<getReverse(876)<<endl;
32 |     return 0;
33 | }
34 | 


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/GFG TCS Sheet/03]. Problems on Number Series/14_Sum_of_digits_of_number.cpp:
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 1 | class Solution{
 2 | public:
 3 |     int sumOfDigits(int N){
 4 |         //code here
 5 |         int sum=0;
 6 |         while(N>0){
 7 |             sum+=N%10;
 8 |             N/=10;
 9 |         }
10 |         return sum;
11 |     }
12 | };


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/GFG TCS Sheet/03]. Problems on Number Series/19_Perfect_number.cpp:
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 1 | // User function Template for C++
 2 | 
 3 | class Solution {
 4 |   public:
 5 |     int factorial(int n){
 6 |         int fact=1;
 7 |         while(n>0){
 8 |             fact*=n;
 9 |             n--;
10 |         }
11 |         return fact;
12 |     }  
13 | 
14 |     int isPerfect(int N) {
15 |         // code here
16 |         int res=0;
17 |         vector<int>v;
18 |         int temp=N;
19 |         while(temp>0){
20 |             v.push_back(temp%10);
21 |             temp/=10;
22 |         }
23 |         for(int i=0; i<v.size(); i++){
24 |             res+=factorial(v[i]);
25 |         }
26 |         return res==N;
27 |         
28 |     }
29 | };


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/GFG TCS Sheet/03]. Problems on Number Series/20_Palindrome_in_a_given_range.cpp:
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 1 | // User function Template for C++
 2 | 
 3 | class Solution {
 4 |   public:
 5 |     int isDigitSumPalindrome(int N) {
 6 |         // code here
 7 |         vector<int>v;
 8 |         int temp=N;
 9 |         int sum=0;
10 |         while(temp>0){
11 |             sum+=temp%10;
12 |             temp/=10;
13 |         }
14 |        
15 |         while(sum>0){
16 |             v.push_back(sum%10);
17 |             sum/=10;
18 |         }
19 |         int l=0;
20 |         int r=v.size()-1;
21 |         
22 |         if(v.size()==1){
23 |             return 1;
24 |         }
25 |         
26 |         while(l<r){
27 |             if(v[l]!=v[r]){
28 |                 return 0;
29 |             }
30 |             l++;
31 |             r--;
32 |         }
33 |         return 1;
34 |     }
35 | };


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/GFG TCS Sheet/03]. Problems on Number Series/22_Abundant_Number.cpp:
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 1 | /*
 2 | A number n is said to be an Abundant Number if the sum of all the proper divisors of the number denoted by sum(n) is greater than the value of the number n. And the difference between these two values is called abundance. 
 3 | Mathematically, if the below condition holds the number is said to be an Abundant number:
 4 | 
 5 | sum(n)> n
 6 | abundance =  sum(n) - n
 7 | sum(n): aliquot sum - The sum of all proper divisors of n
 8 | Given a number n, our task is to find if this number is an Abundant number or not. 
 9 | The first few Abundant Numbers are: 12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66 ….. 
10 | 
11 | Abundant Numbers
12 | 
13 | Examples:
14 | 
15 | Input: 21
16 | Output: NO
17 | 
18 | Input: 12
19 | Output: YES
20 | 
21 | Input: 17
22 | Output: NO
23 | */ 
24 | 
25 | #include<iostream>
26 | using namespace std;
27 | 
28 | string isAbundant(int n){
29 |     // vector<int>v;
30 |     int sum=0;
31 |     for(int i=1; i<n; i++){
32 |         if(n%i==0){
33 |             sum+=i;
34 |         }
35 |     }
36 | 
37 |     if(sum>n){
38 |         return "YES";
39 |     }else{
40 |         return "NO";   
41 |     }
42 | }
43 | 
44 | int main()
45 | {
46 |     int n=21;
47 |     cout<<isAbundant(n)<<endl;
48 |     cout<<isAbundant(12)<<endl;
49 |     cout<<isAbundant(17)<<endl;
50 |     return 0;
51 | }
52 | 


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/GFG TCS Sheet/03]. Problems on Number Series/23_Sum_of_first_N_natural_numbers.cpp:
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 1 | /*
 2 | Given a number n, find the sum of the first natural numbers.
 3 | 
 4 | Examples : 
 5 | 
 6 | Input: n = 3
 7 | Output: 6
 8 | Explanation:
 9 | Note that 1 + 2 + 3 = 6
10 | 
11 | Input  : 5
12 | Output : 15 
13 | Explanation :
14 | Note that 1 + 2 + 3 + 4 + 5 = 15
15 | */ 
16 | #include<iostream>
17 | using namespace std;
18 | 
19 | int getSum(int n){
20 |     return n*(n+1)/2;
21 | }
22 | 
23 | int main(){
24 |     int n=4;
25 |     cout<<getSum(n);
26 |     return 0;
27 | }


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/GFG TCS Sheet/03]. Problems on Number Series/24_Sum_of_natural_numbers_in_range_L_to_R.cpp:
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 1 | /*
 2 | Given a range L and R, the task is to find the sum of all natural numbers in range L to R. 
 3 | Examples: 
 4 |  
 5 | 
 6 | Input: L = 2, R = 5
 7 | Output: 14
 8 | 2 + 3 + 4 + 5 = 14
 9 | 
10 | Input: L = 10, R = 20
11 | Output: 165
12 | */ 
13 | 
14 | #include<iostream>
15 | using namespace std;
16 | 
17 | int getSum(int l, int r){
18 |     int sum=0;
19 |     for(int i=l; i<=r; i++){
20 |         sum+=i;
21 |     }
22 |     return sum;
23 | }
24 | 
25 | int main()
26 | {
27 |     int L=2; 
28 |     int R=5;
29 |     cout<<getSum(L, R);
30 |     return 0;
31 | }
32 | 


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/GFG TCS Sheet/03]. Problems on Number Series/29_Check_if_a_number_is_palondrome_or_not.cpp:
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 1 | // User function Template for C++
 2 | 
 3 | class Solution {
 4 |   public:
 5 |     int isDigitSumPalindrome(int N) {
 6 |         // code here
 7 |         vector<int>v;
 8 |         int temp=N;
 9 |         int sum=0;
10 |         while(temp>0){
11 |             sum+=temp%10;
12 |             temp/=10;
13 |         }
14 |        
15 |         while(sum>0){
16 |             v.push_back(sum%10);
17 |             sum/=10;
18 |         }
19 |         int l=0;
20 |         int r=v.size()-1;
21 |         
22 |         if(v.size()==1){
23 |             return 1;
24 |         }
25 |         
26 |         while(l<r){
27 |             if(v[l]!=v[r]){
28 |                 return 0;
29 |             }
30 |             l++;
31 |             r--;
32 |         }
33 |         return 1;
34 |     }
35 | };


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/GFG TCS Sheet/03]. Problems on Number Series/30_Largest_and_smallest_digit_of_a_Number.cpp:
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 1 | /*
 2 | Given a number N. The task is to find the largest and the smallest digit of the number.
 3 | Examples :
 4 | 
 5 | Input : N = 2346 
 6 | Output : 6 2 
 7 | 6 is the largest digit and 2 is smallest
 8 | Input : N = 5 
 9 | Output : 5 5
10 | */ 
11 | 
12 | #include<bits/stdc++.h>
13 | using namespace std;
14 | 
15 | void getLargestAndSmallest(int n){
16 |     vector<int>v;
17 |     while(n>0){
18 |         v.push_back(n%10);
19 |         n/=10;
20 |     }
21 |     sort(v.begin(), v.end());
22 |     cout<<v[v.size()-1]<<" "<<v[0];
23 |     cout<<endl;
24 | }
25 | 
26 | int main()
27 | {
28 |     int n=2346;
29 |     getLargestAndSmallest(n);
30 |     getLargestAndSmallest(5);
31 |     return 0;
32 | }
33 | 


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/GFG TCS Sheet/03]. Problems on Number Series/34_Area_of_Circle_Reclangle_and_Right_angled_Trinagle.cpp:
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 1 | class Solution {
 2 |   public:
 3 |     vector<int> getAreas(int L , int W , int B , int H , int R) {
 4 |         // code here
 5 |         vector<int>v;
 6 |         v.push_back(L*W); // Rectangle
 7 |         v.push_back(0.5*B*H); // Right Angled Triangle
 8 |         v.push_back(3.14*(R*R)); // Circle
 9 |         return v;
10 |     }
11 | };


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/GFG TCS Sheet/03]. Problems on Number Series/README.md:
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1 | # Problems on Number Series


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/GFG TCS Sheet/04]. Problems on Conversions/README.md:
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1 | # Problems on Conversions


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/GFG TCS Sheet/05]. Sorting Algorithms/01_Bubble_Sort.cpp:
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 1 | #include<iostream>
 2 | using namespace std;
 3 | 
 4 | // Best Case TC: O(n)
 5 | // Average Case TC: O(n*n)
 6 | // Worst Case TC: O(n*n)
 7 | // Bubble Sort is Stable
 8 | // Bubble Sort is Adaptive
 9 | int BubbleSort(int arr[], int n)
10 | {
11 |     int flag;
12 |     for(int i=0; i<n-1; i++){
13 |         flag=0;
14 |         for(int j=0; j<n-1-i; j++){
15 |             if(arr[j]>arr[j+1]){
16 |                 swap(arr[j], arr[j+1]);
17 |                 flag=1;
18 |             }
19 |         } 
20 |         if(flag==0){
21 |             break;
22 |         }
23 |     }
24 |     cout<<endl;
25 | }
26 | 
27 | int main(){
28 |     int arr[]{3,4,2,1,5,6,9,8,7};
29 |     int n=9;
30 |     for(auto x: arr) cout<<x<<" ";
31 |     BubbleSort(arr, n);
32 |     for(auto x: arr) cout<<x<<" ";
33 |     return 0;
34 | }


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/GFG TCS Sheet/05]. Sorting Algorithms/03_Insertion_sort.cpp:
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 1 | #include<bits/stdc++.h>
 2 | using namespace std;
 3 | 
 4 | // Worst Case TC: O(n*n)
 5 | // Average Case TC: O(n*n)
 6 | void InsertionSort(int arr[], int n){
 7 |     for(int i=1; i<n; i++){
 8 |         int j=i-1;
 9 |         int x=arr[i];
10 |         while(j>=0 && arr[j]>x){
11 |             arr[j+1]=arr[j];
12 |             j--;
13 |         }
14 |         arr[j+1]=x;
15 |     }
16 |     cout<<endl;
17 | }
18 | 
19 | int main(){
20 |     int arr[]{3,2,4,1,5,7,6,9,8};
21 |     int n=9;
22 |     for(auto x: arr) cout<<x<<" ";
23 |     InsertionSort(arr, n);
24 |     for(auto x: arr) cout<<x<<" ";
25 |     return 0;
26 | }


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/GFG TCS Sheet/05]. Sorting Algorithms/README.md:
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1 | # Sorting Algorithms


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/GFG TCS Sheet/README.md:
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1 | # [GFG TCS Sheet](https://www.geeksforgeeks.org/tcs-sde-sheet-interview-questions-and-answers/) 
2 | 
3 | - 01]. [Problems on Array](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet/01%5D.%20Problems%20on%20Array)
4 | - 02]. [Problems on String](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet/02%5D.%20Problems%20on%20String)
5 | - 03]. [Problems on Number Series](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet/03%5D.%20Problems%20on%20Number%20Series)
6 | - 04]. [Problems on Conversions](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet/04%5D.%20Problems%20on%20Conversions)
7 | - 05]. [Sorting Algorithms](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet/05%5D.%20Sorting%20Algorithms)


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/README.md:
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1 | # TCS NQT Coding Sheets 
2 | 
3 | ## `INDEX`
4 | 
5 | ### 1].  [GFG TCS Sheet](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/GFG%20TCS%20Sheet)
6 | ### 2].  [Striver TCS Sheet](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/Striver%20TCS%20Sheet)
7 | 


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/Striver TCS Sheet/01]. Arrays/01_Find_the_smallest_number_in_an_array.cpp:
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 1 | /*
 2 | Problem Statement: Given an array, we have to find the smallest element in the array.
 3 | 
 4 | Examples:
 5 | 
 6 | Example 1:
 7 | Input: arr[] = {2,5,1,3,0};
 8 | Output: 0
 9 | Explanation: 0 is the smallest element in the array. 
10 | 
11 | Example2: 
12 | Input: arr[] = {8,10,5,7,9};
13 | Output: 5
14 | Explanation: 5 is the smallest element in the array.
15 | 
16 | */ 
17 | 
18 | #include<iostream>
19 | #include<vector>
20 | #include<algorithm>
21 | 
22 | using namespace std;
23 | 
24 | // TC: O(n*log(n))
25 | // SC: O(n)
26 | int getSmallest(vector<int> arr){
27 |     sort(arr.begin(), arr.end());
28 |     return arr[0];
29 | }
30 | 
31 | int main(){
32 |     vector<int>arr1 = {23, 24, 53, 53, 14, 456, 755};
33 |     vector<int>arr2 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
34 | 
35 |     cout<<getSmallest(arr1)<<endl;
36 |     cout<<getSmallest(arr2)<<endl;
37 | }


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/Striver TCS Sheet/01]. Arrays/02_Find_the_Largest_element_in_an_array.cpp:
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 1 | /*
 2 | 
 3 | Find the Largest element in an array
 4 | Problem Statement: Given an array, we have to find the largest element in the array.
 5 | 
 6 | Examples:
 7 | 
 8 | Example 1:
 9 | Input: arr[] = {2,5,1,3,0};
10 | Output: 5
11 | Explanation: 5 is the largest element in the array. 
12 | 
13 | Example2: 
14 | Input: arr[] = {8,10,5,7,9};
15 | Output: 10
16 | Explanation: 10 is the largest element in the array. 
17 | 
18 | */
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 |  
23 | // TC: O(n*log(n))
24 | // SC: O(n)
25 | int getLargest(vector<int>& arr){
26 |     sort(arr.begin(), arr.end());
27 |     return arr[arr.size()-1];
28 | }
29 | 
30 |  
31 | int main() {
32 |     vector<int> arr1 = {2,5,1,3,0};
33 |     vector<int> arr2 = {8,10,5,7,9};
34 |    
35 |     cout<<"The Largest element in the array is: "<<getLargest(arr1)<<endl;
36 |     cout<<"The Largest element in the array is: "<<getLargest(arr2);
37 |    
38 |     return 0;
39 | }


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/Striver TCS Sheet/01]. Arrays/03_Find_Second_Smallest_and_Second_Largest_Element_in_an_array.cpp:
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 1 | /*
 2 | Find Second Smallest and Second Largest Element in an array
 3 | Problem Statement: Given an array, find the second smallest and second largest element in the array. Print ‘-1’ in the event that either of them doesn’t exist.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: [1,2,4,7,7,5]
 9 | Output: Second Smallest : 2
10 | 	Second Largest : 5
11 | Explanation: The elements are as follows 1,2,3,5,7,7 and hence second largest of these is 5 and second smallest is 2
12 | 
13 | Example 2:
14 | Input: [1]
15 | Output: Second Smallest : -1
16 | 	Second Largest : -1
17 | Explanation: Since there is only one element in the array, it is the largest and smallest element present in the array. There is no second largest or second smallest element present.
18 | */ 
19 | 
20 | 
21 | #include<bits/stdc++.h>
22 | using namespace std;
23 | 
24 | // Method 1: 
25 | // TC: O(n*log(n))
26 | // SC: O(1)
27 | void getElements1(int arr[], int n){
28 |     if(n<=1){
29 |         cout<<" 2nd Smallest: -1"<<endl;
30 |         cout<<"2nd Largest: -1"<<endl;
31 |     }
32 | 
33 |     sort(arr, arr+n);
34 |     cout<<"2nd Smallest: "<<arr[1]<<endl;
35 |     cout<<"2nd Largest: "<<arr[n-2]<<endl;
36 | }
37 | 
38 | // Method 2: 
39 | // TC: O(n)
40 | // SC: O(1)
41 | void getElements2(int arr[], int n){
42 |     int smallest = INT_MAX; 
43 |     int largest = INT_MIN;
44 |     int sec_smallest = INT_MAX;
45 |     int sec_largest = INT_MIN;
46 | 
47 |     for(int i=0; i<n; i++){
48 |         smallest = min(smallest, arr[i]);
49 |         largest = max(largest, arr[i]);
50 |     }
51 | 
52 |     for(int i=0; i<n; i++){
53 |         if(arr[i] < sec_smallest && arr[i]!=smallest){
54 |             sec_smallest=arr[i];
55 |         }
56 | 
57 |         if(arr[i] > sec_largest && arr[i]!=largest){
58 |             sec_largest=arr[i];
59 |         }
60 | 
61 |     }
62 | 
63 |     cout<<"2nd Smallest: "<<sec_smallest<<endl;
64 |     cout<<"2nd Largest: "<<sec_largest<<endl;
65 | }
66 | 
67 | int main(){
68 |     int arr[]={1,2,4,6,7,5};
69 |     int n = sizeof(arr)/sizeof(arr[0]);
70 |     getElements1(arr,n);
71 |     cout<<endl<<endl;
72 | 
73 |     getElements2(arr,n);
74 |     return 0;
75 | }


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/Striver TCS Sheet/01]. Arrays/04_Reverse_a_given_Array.cpp:
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 1 | /*
 2 | Reverse a given Array
 3 | Problem Statement: You are given an array. The task is to reverse the array and print it. 
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5, arr[] = {5,4,3,2,1}
 9 | Output: {1,2,3,4,5}
10 | Explanation: Since the order of elements gets reversed the first element will occupy the fifth position, the second element occupies the fourth position and so on.
11 | 
12 | Example 2:
13 | Input: N=6 arr[] = {10,20,30,40}
14 | Output: {40,30,20,10}
15 | Explanation: Since the order of elements gets reversed the first element will occupy the fifth position, the second element occupies the fourth position and so on.
16 | */ 
17 | 
18 | #include <iostream>
19 | using namespace std;
20 | 
21 | void reverseArray(int arr[], int n){
22 |     int i=0, j=n-1;
23 |     while(i<j){
24 |         swap(arr[i], arr[j]);
25 |         i++;
26 |         j--;
27 |     }
28 | 
29 |     for(int i=0; i<n; i++) 
30 |         cout<<arr[i]<<" ";
31 |     cout<<endl;
32 | }
33 | 
34 | int main() {
35 |    int n = 5;
36 |    int arr[] = {5,4,3,2,1};
37 |    reverseArray(arr, n);
38 |    return 0;
39 | }


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/Striver TCS Sheet/01]. Arrays/05_Count_frequency_of_each_element_in_the_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Count frequency of each element in the array
 3 | Problem statement: Given an array, we have found the number of occurrences of each element in the array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: arr[] = {10,5,10,15,10,5};
 9 | Output: 10  3
10 | 	 5  2
11 |         15  1
12 | Explanation: 10 occurs 3 times in the array
13 | 	      5 occurs 2 times in the array
14 |               15 occurs 1 time in the array
15 | 
16 | Example2: 
17 | Input: arr[] = {2,2,3,4,4,2};
18 | Output: 2  3
19 | 	3  1
20 |         4  2
21 | Explanation: 2 occurs 3 times in the array
22 | 	     3 occurs 1 time in the array
23 |              4 occurs 2 time in the array
24 | */ 
25 | 
26 | #include <bits/stdc++.h>
27 | using namespace std;
28 | 
29 |  
30 | // Method 1: 
31 | // TC: O(n)
32 | // SC: O(n)
33 | void countFreq1(int arr[], int n){
34 |     map<int, int>mp;
35 | 
36 |     for(int i=0; i<n; i++){
37 |         mp[arr[i]]++;
38 |     }
39 | 
40 |     for(auto x: mp){
41 |         cout<<x.first<<" "<<x.second<<endl;
42 |     }
43 | }
44 |  
45 | int main()
46 | {
47 |     int arr[] = {10,5,10,15,10,5};
48 |     int n = sizeof(arr) / sizeof(arr[0]);
49 |     countFreq1(arr, n);
50 |     return 0;
51 | }


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/Striver TCS Sheet/01]. Arrays/06_Rearrange_array_in_increasing_decreasing_order.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Rearrange array in increasing-decreasing order
 3 | Problem Statement: Rearrange the array such that the first half is arranged in increasing order, and the second half is arranged in decreasing order
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 8 7 1 6 5 9
 9 | Output: 1 5 6 9 8 7
10 | Explanation: First three elements are in the ascending order and next three elements are in the descending order.
11 | 
12 | Example 2:
13 | Input: 4 2 8 6 15 5 9 20
14 | Output: 2 4 5 6 20 15 9 8
15 | */ 
16 | 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | // TC: O(n*log(n))
21 | // SC: O(1)
22 | void reArrange(vector<int>& arr, int n){
23 |     sort(arr.begin(), arr.end());
24 | 
25 |     for(int i=0; i<n/2; i++){
26 |         cout<<arr[i]<<" ";
27 |     }
28 |     for(int i=n-1; i>=n/2; i--){
29 |         cout<<arr[i]<<" ";
30 |     }
31 | }
32 | 
33 | int main()
34 | {
35 | 	vector<int>arr = {8, 7, 1, 6, 5, 9};
36 | 	int n = arr.size();
37 |     reArrange(arr, n);
38 | 	return 0;
39 | }


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/Striver TCS Sheet/01]. Arrays/07_Calculate_Sum_of_the_Elements_of_the_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Calculate Sum of the Elements of the Array
 3 | Problem Statement: Given an array, we have to find the sum of all the elements in the array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5, array[] = {1,2,3,4,5}
 9 | Output: 15
10 | Explanation: Sum of all the elements is 1+2+3+4+5 = 15
11 | 
12 | Example 2:
13 | Input:  N=6, array[] = {1,2,1,1,5,1}
14 | Output: 11
15 | Explanation: Sum of all the elements is 1+2+1+1+5+1 = 11
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | // Method 1: 
22 | // TC: O(n)
23 | // SC: O(1)
24 | int getSum1(vector<int>& arr){
25 |     int n = arr.size();
26 |     int sum = 0;
27 | 
28 |     for(auto x: arr){
29 |         sum+=x;
30 |     }
31 |     return sum;
32 | }
33 | 
34 | // Method 2: 
35 | // TC: O(n)
36 | // SC: O(1)
37 | int getSum2(vector<int>& arr){
38 |     int sum = 0;
39 |     return accumulate(arr.begin(), arr.end(), sum);
40 | }
41 | 
42 | int main() {
43 | 	int n = 5;
44 | 	vector<int>arr = {1, 2, 3, 4, 5};
45 | 	int sum = 0;
46 | 	cout<<getSum1(arr)<<endl;
47 | 
48 |     cout<<getSum2(arr)<<endl;
49 | }


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/Striver TCS Sheet/01]. Arrays/09_Average_of_all_the_elements_in_the_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Average of all the elements in the array
 3 | Problem Statement: Given an array, we have to find the average of all the elements in the array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5, array[] = {1,2,3,4,5}
 9 | Output: 3
10 | Explanation: Average is the sum of all the elements divided by number of elements.Therefore (1+2+3+4+5)/5 = 3.
11 | 
12 | Example 2:
13 | Input:  N=6, array[] = {1,2,1,1,5,1}
14 | Output: 1.8
15 | Explanation: Average is the sum of all the elements divided by number of elements.Therefore (1+2+1+1+5+1)/6 = 1.8
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | // TC: O(n)
22 | // SC: O(1)
23 | double getAverage(vector<int>& arr){
24 |     int n = arr.size();
25 |     double avg=0;
26 |     double sum = 0; 
27 |     return accumulate(arr.begin(), arr.end(), sum)/n;
28 | }
29 | 
30 | int main(){
31 |     int n = 5;
32 | 	vector<int> arr= {1,2,1,1,5,1};
33 |     cout<<getAverage(arr)<<endl;
34 |     return 0;
35 | }


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/Striver TCS Sheet/01]. Arrays/10_Find_Median_of_the_given_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find Median of the given Array
 3 | Problem Statement: Given an unsorted array, find the median of the given array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: [2,4,1,3,5] 5 
 9 | Output: 3
10 | 
11 | Example 2:
12 | Input: [2,5,1,7]
13 | Output: 3.5
14 | */ 
15 | 
16 | #include<bits/stdc++.h>
17 | using namespace std;
18 | 
19 | void getMedian(int arr[], int n){
20 |     double median=0;
21 |     sort(arr, arr+n);
22 | 
23 |     if(n%2==0){
24 |         cout<<(double)(arr[(n/2)]+arr[(n/2)-1])/2;
25 |     }
26 |     else{
27 |         cout<<arr[(n/2)+1];
28 |     }
29 | }
30 | 
31 | int main(){
32 |     int arr[] = {2,5,1,7};
33 |     int n = sizeof(arr)/sizeof(arr[0]);
34 |     cout<<"The median of the array is: ";
35 |     getMedian(arr,n);
36 |     return 0;
37 | }


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/Striver TCS Sheet/01]. Arrays/11_Remove_Duplicates_in-place_from_Sorted_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove Duplicates in-place from Sorted Array
 3 | Problem Statement: Given an integer array sorted in non-decreasing order, remove the duplicates in place such that each unique element appears only once. The relative order of the elements should be kept the same.
 4 | 
 5 | If there are k elements after removing the duplicates, then the first k elements of the array should hold the final result. It does not matter what you leave beyond the first k elements.
 6 | 
 7 | Note: Return k after placing the final result in the first k slots of the array.
 8 | 
 9 | Examples:
10 | 
11 | Example 1: 
12 | 
13 | Input: arr[1,1,2,2,2,3,3]
14 | 
15 | Output: arr[1,2,3,_,_,_,_]
16 | 
17 | Explanation: Total number of unique elements are 3, i.e[1,2,3] and Therefore return 3 after assigning [1,2,3] in the beginning of the array.
18 | 
19 | Example 2: 
20 | 
21 | Input: arr[1,1,1,2,2,3,3,3,3,4,4]
22 | 
23 | Output: arr[1,2,3,4,_,_,_,_,_,_,_]
24 | 
25 | Explanation: Total number of unique elements are 4, i.e[1,2,3,4] and Therefore return 4 after assigning [1,2,3,4] in the beginning of the array.
26 | */ 
27 | 
28 | #include<bits/stdc++.h>
29 | using namespace std;
30 | 
31 | // Method 1: 
32 | // TC: O(n)
33 | // SC: O(1)
34 | void removeSuplicates1(vector<int>& arr){
35 |     int n = arr.size();
36 |     cout<<arr[0]<<" ";
37 |     for(int i=0; i<n; i++){
38 |         if(arr[i]!=arr[i-1] && i!=0){
39 |             cout<<arr[i]<<" ";
40 |         }
41 |     }
42 | }
43 | 
44 | // Method 2: Not-Inplace
45 | // TC: O(n)
46 | // SC: O(n)
47 | void removeSuplicates2(vector<int>& arr){
48 |     set<int>s(arr.begin(), arr.end());
49 |     for(auto x: s) cout<<x<<" ";
50 | }
51 | 
52 | 
53 | int main()
54 | {
55 |     vector<int>arr{1,1,1,2,2,3,3,3,3,4,4};
56 |     removeSuplicates1(arr);
57 |     cout<<endl;
58 |     removeSuplicates2(arr);
59 |     return 0;
60 | }
61 | 


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/Striver TCS Sheet/01]. Arrays/12_Remove_duplicates_from_unsorted_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove Duplicates From an Unsorted Array
 3 | Problem Statement: Given an unsorted array, remove duplicates from the array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: arr[]={2,3,1,9,3,1,3,9}
 9 | Output:  {2,3,1,9}
10 | 
11 | Explanation: Removed all the duplicate elements
12 | 
13 | Example 2:
14 | Input: arr[]={4,3,9,2,4,1,10,89,34}
15 | Output: {3,4,9,2,1,10,34,89}
16 | Explanation: Removed all the duplicate elements
17 | */ 
18 | 
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 | 
23 | // Method 1: 
24 | // TC: O(n)
25 | // SC: O(1)
26 | void removeSuplicates1(vector<int>& arr){
27 |     int n = arr.size();
28 |     sort(arr.begin(), arr.end());
29 |     cout<<arr[0]<<" ";
30 |     for(int i=0; i<n; i++){
31 |         if(arr[i]!=arr[i-1] && i!=0){
32 |             cout<<arr[i]<<" ";
33 |         }
34 |     }
35 | }
36 | 
37 | // Method 2: 
38 | // TC: O(n)
39 | // SC: O(n)
40 | void removeSuplicates2(vector<int>& arr){
41 |     set<int>s(arr.begin(), arr.end());
42 |     for(auto x: s) cout<<x<<" ";
43 | }
44 | 
45 | // Method 3: 
46 | // TC: O(n)
47 | // SC: O(n)
48 | void removeSuplicates3(vector<int>& arr){
49 |     int n = arr.size();
50 |     map<int, int>mp;
51 |     for(int i=0; i<n; i++){
52 |         mp[arr[i]]++;
53 |     }
54 |     for(auto x: mp) cout<<x.first<<" ";
55 | }
56 | 
57 | 
58 | int main()
59 | {
60 |     vector<int>arr{2,3,1,9,3,1,3,9};
61 |     removeSuplicates1(arr);
62 |     cout<<endl;
63 |     removeSuplicates2(arr);
64 |     cout<<endl;
65 |     removeSuplicates3(arr);
66 |     return 0;
67 | }
68 | 


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/Striver TCS Sheet/01]. Arrays/13_Adding_Element_in_an_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Adding Element in an Array
 3 | Problem Statement: Given an array of N integers, write a program to add an array element at the beginning, end, and at a specific position.
 4 | 
 5 | Example:
 6 | Input: N = 5, array[] = {1,2,3,4,5}
 7 | insertbeginning(6)
 8 | insertending(7)
 9 | insertatpos(8,4)
10 | Output: 6,1,2,8,3,4,5,7
11 | Explanation: 6 is added at the beginning and 7 is added at the end and 8 is added at position 4
12 | */ 
13 | 
14 | #include<bits/stdc++.h>
15 | using namespace std;
16 | 
17 | // Inserting the element at the BEGINNING
18 | void insertatbegin(int arr[], int n, int value){
19 |     for(int i=n-1; i>=0; i--){
20 |         arr[i+1]=arr[i];
21 |     }
22 |     arr[0]=value;
23 |     n= n+1;
24 | }
25 | 
26 | // Inserting at the END
27 | void insertatEnd(int arr[], int n, int value){
28 |     arr[n]=value;
29 | }
30 | 
31 | // Insertion at specific position
32 | void insertatposition(int arr[], int n, int value, int pos){
33 |     for(int i=n-1; i>=pos; i--){
34 |         arr[i]=arr[i-1];
35 |     }
36 |     arr[pos-1]=value;
37 | 
38 | }
39 | 
40 | int main()
41 | {
42 |     int arr[9]={10,9,14,8,20,48,16,9};
43 |     int n=8;
44 |     int value=40;
45 |     cout<<"Before inserting the value at beginning:"<<endl;
46 |      for(int i=0;i<n;i++)
47 |     {
48 |         cout<<arr[i]<<" ";
49 |     }
50 |     cout<<endl;
51 | 
52 |     insertatbegin(arr,n,value);
53 |     cout<<"After inserting the value at beginning:"<<endl;
54 |     for(int i=0;i<=n;i++)
55 |     {
56 |         cout<<arr[i]<<" ";
57 |     }
58 |     cout<<endl<<endl;
59 | 
60 | 
61 | 
62 |     // ----------------------INSERTING at the end --------------------------
63 |     value = 999;
64 |     cout<<"Before inserting the value at beginning:"<<endl;
65 |      for(int i=0;i<n;i++)
66 |     {
67 |         cout<<arr[i]<<" ";
68 |     }
69 |     cout<<endl;
70 |     insertatEnd(arr,n,value);
71 |     cout<<"After inserting the value at beginning:"<<endl;
72 |     for(int i=0;i<=n;i++)
73 |     {
74 |         cout<<arr[i]<<" ";
75 |     }
76 |     cout<<endl<<endl;
77 | 
78 |     // ------------------ INSERTING at Specific position -------------------
79 |     value = 100;
80 |     int pos = 5;
81 |     
82 |     cout<<"Before inserting the value at Specific location:"<<endl;
83 |      for(int i=0;i<n;i++)
84 |     {
85 |         cout<<arr[i]<<" ";
86 |     }
87 |     cout<<endl;
88 |     insertatposition(arr,n,value,pos);
89 |     cout<<"After inserting the value at specific location:"<<endl;
90 |     for(int i=0;i<=n;i++)
91 |     {
92 |         cout<<arr[i]<<" ";
93 |     }
94 |     cout<<endl;
95 | 
96 |     return 0;
97 | }


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/Striver TCS Sheet/01]. Arrays/14_Find_all_repeating_elements_in_an_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find all repeating elements in an array
 3 | Problem Statement: Find all the repeating elements present in an array.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 
 9 | Arr[] = [1,1,2,3,4,4,5,2]
10 | Output:
11 |  1,2,4
12 | Explanation:
13 |  1,2 and 4 are the elements which are occurring more than once.
14 | 
15 | Example 2:
16 | Input:
17 |  Arr[] = [1,1,0]
18 | Output:
19 |  1
20 | Explanation:
21 |  Only 1 is occurring more than once in the given array.
22 | */ 
23 | 
24 | #include<bits/stdc++.h>
25 | using namespace std;
26 | 
27 | // Method 1;
28 | // TC: O(n*log(n))
29 | // SC: O(1)
30 | void findRepeatingElements1(int arr[], int n){
31 |     sort(arr, arr+n);
32 | 
33 |     for(int i=1; i<n; i++){
34 |         if(arr[i]==arr[i-1])
35 |             cout<<arr[i]<<" ";
36 |     }
37 |     cout<<endl;
38 | }
39 | 
40 | 
41 | // Method 2: 
42 | // TC: O(n)
43 | // SC: O(n)
44 | void findRepeatingElements2(int arr[], int n){
45 |     map<int, int>mp;
46 | 
47 |     for(int i=0; i<n; i++){
48 |         mp[arr[i]]++;
49 |     }
50 | 
51 |     for(auto x: mp){
52 |         if(x.second>1)
53 |             cout<<x.first<<" ";
54 |     }
55 | }
56 | 
57 | int main()
58 | {
59 |     int arr[] = {1,1,2,3,4,4,5,2};
60 |     int n = sizeof(arr)/sizeof(arr[0]);
61 | 
62 |     findRepeatingElements1(arr,8);
63 | 
64 |     findRepeatingElements2(arr,8);
65 | 
66 |     return 0;
67 | }
68 | 
69 | 


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/Striver TCS Sheet/01]. Arrays/15_Find_all_the_non_repeating_elements_in_an_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find all the non-repeating elements in an array
 3 | Problem Statement: Find all the non-repeating elements for a given array. Outputs can be in any order.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input:
 9 |  Nums = [1,2,-1,1,3,1]
10 | Output:
11 |  2,-1,3
12 | Explanation:
13 |  1 is the only element in the given array which occurs thrice in the array. -1,2,3 occurs only once and hence, these are non-repeating elements of the given array.
14 | 
15 | Example 2:
16 | Input:
17 |  Nums = [1,2,3]
18 | Output:
19 |  1,2,3
20 | Explanation:
21 |  All elements present in the array occur once. Hence, every element is non-repeating.
22 | */ 
23 | 
24 | #include<bits/stdc++.h>
25 | using namespace std;
26 | 
27 | // Method 1: 
28 | // TC: O(n)
29 | // SC: O(n)
30 | void findNonRepeatingElement(vector<int>& nums){
31 |     int n = nums.size();
32 |     map<int, int>mp;
33 | 
34 |     for(int i=0; i<n; i++){
35 |         mp[nums[i]]++;
36 |     }
37 | 
38 |     for(auto x: mp){
39 |         if(x.second==1){
40 |             cout<<x.first<<" ";
41 |         }
42 |     }
43 |     cout<<endl;
44 | }
45 | 
46 | 
47 | int main() {
48 |     vector<int> nums = {1,2,-1,1,3,1};
49 |     cout<<"Non-repeating numbers are: "<<endl;
50 |     findNonRepeatingElement(nums);
51 |     
52 |     return 0;
53 | }


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/Striver TCS Sheet/01]. Arrays/17_Maximum_Product_Subarray_in_an_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Maximum Product Subarray in an Array
 3 | Problem Statement: Given an array that contains both negative and positive integers, find the maximum product subarray.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input:
 9 |  Nums = [1,2,3,4,5,0]
10 | Output:
11 |  120
12 | Explanation:
13 |  In the given array, we can see 1×2×3×4×5 gives maximum product value.
14 | 
15 | 
16 | Example 2:
17 | Input:
18 |  Nums = [1,2,-3,0,-4,-5]
19 | Output:
20 |  20
21 | Explanation:
22 |  In the given array, we can see (-4)×(-5) gives maximum product value.
23 | */ 
24 | 
25 | 
26 | #include<bits/stdc++.h>
27 | using namespace std;
28 | 
29 | // Method 1: 
30 | // TC: O(n*n)
31 | // SC: O(1)
32 | int maxProductSubArray(vector<int>& nums){
33 |     int n = nums.size();
34 |     int max_product = 1;
35 | 
36 |     for(int i=0; i<n; i++){
37 |         int curr_product = 1;
38 |         for(int j=0; j<n; j++){
39 |             curr_product = curr_product * nums[j];
40 |             max_product = max(curr_product, max_product);
41 |         }
42 |     }
43 |     return max_product;
44 | }
45 | 
46 | int main() {
47 |     vector<int> nums = {1,2,3,4,5,0};
48 |     cout<<"The maximum product subarray: "<<maxProductSubArray(nums);
49 |     return 0;
50 | }


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/Striver TCS Sheet/01]. Arrays/18_Replace_elements_by_its_rank_in_the_array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Replace elements by its rank in the array
 3 | Replace elements by its rank in the array
 4 | 
 5 | Problem Statement: Given an array of N integers, the task is to replace each element of the array by its rank in the array.
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input: 20 15 26 2 98 6
11 | Output: 4 3 5 1 6 2
12 | Explanation: When sorted,the array is 2,6,15,20,26,98. So the rank of 2 is 1,rank of 6 is 2,rank of 15 is 3 and so…
13 | 
14 | Example 2:
15 | Input: 1 5 8 15 8 25 9
16 | Output: 1 2 3 5 3 6 4
17 | Explanation: When sorted,the array is 1,5,8,8,9,15,25. So the rank of 1 is 1,rank of 5 is 2,rank of 8 is 3 and so…
18 | */ 
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 | 
23 | void ReplaceElement(int arr[], int n){
24 |     vector<int>v(arr, arr+n);
25 |     sort(v.begin(), v.end());
26 | 
27 |     for(int i=0; i<n; i++){
28 |         for(int j=0; j<n; j++){
29 |             if(arr[i]==v[j]){
30 |                 arr[i]=j+1;
31 |             }
32 |         }
33 |     }
34 |     
35 |     for(int i=0; i<n; i++){
36 |         cout<<arr[i]<<" ";
37 |     }
38 |     
39 | }
40 | 
41 | int main()
42 | {
43 | 	int n = 6;
44 | 	int arr[n] = {20, 15, 26, 2, 98, 6};
45 | 	ReplaceElement(arr, n);
46 |     return 0;
47 | }


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/Striver TCS Sheet/01]. Arrays/19_Sort_Elements_of_an_Array_by_Frequency.cpp:
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 1 | /*
 2 | Sort Elements of an Array by Frequency
 3 | 
 4 | Problem Statement: Given an array of integers, having some duplicate elements, sort the array by frequency.
 5 | 
 6 | Examples:
 7 | 
 8 | Example 1:
 9 | Input: N = 8, array[] = {1,2,3,2,4,3,1,2}
10 | Output: 2 2 2 1 1 3 3 4 
11 | Explanation: Since  2 is present 3 times in an array , so print it 3 times ,then print ‘1’ 2 times and then ‘3’ 2 times and 4 has least frequency, it will be printed at last.
12 | 
13 | Example 2:
14 | Input: N = 6, array[] = {-199,6,7,-199,3,5}
15 | Output: -199 -199 3 5 6 7
16 | Explanation: Since -199 is present 2 times so it will be printed at first , then 3 , 5 ,6 ,7 are present once in array , so print them in their sorted order.
17 | 
18 | */ 
19 | 
20 | 
21 | #include<bits/stdc++.h>
22 | using namespace std;
23 | 
24 | void sortByFreq(int &arr, int n){
25 |     
26 | }
27 | 
28 | int main()
29 | {
30 |     int n=6;
31 |     int arr[]={1,2,3,2,4,3,1,2};    
32 |     sortByFreq(arr, n);
33 |     return 0;
34 | }
35 | 


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/Striver TCS Sheet/01]. Arrays/24_Search_an_Element_in_an_Array.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Search an Element in an Array : Program CPP Java
 3 | Problem Statement: Search an element in an array and return its position
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: array[] = {1,2,3,4,5} k=3                                                                              Output: 2                                                                                                              Explanation: The answer is 2 because 3 is present at 2nd index.
 9 | 
10 | Example 2:
11 | Input: array[]={6,7,9,5,3,10} k=10
12 | Output: 5
13 | Explanation: The answer is 5 because 10 is present at 5th index.
14 | */ 
15 | 
16 | #include<bits/stdc++.h>
17 | using namespace std;
18 | 
19 | // Method 1: Linear Search
20 | // TC: O(n)
21 | // SC: O(1)
22 | int linearSearch(int arr[], int n, int k){
23 |     for(int i=0; i<n; i++){
24 |         if(arr[i]==k){
25 |             return i;
26 |         }
27 |     }
28 |     return -1;
29 | }
30 | 
31 | // Method 2: Binary Search: works only, if array is sorted -> 
32 | // TC: O(log(n))
33 | // SC: O(1)
34 | int binarySearch(int arr[], int n, int k){
35 |     int left = 0;
36 |     int right = n-1;
37 | 
38 |     while(left<=right){
39 |         int mid = (left+right)/2;
40 | 
41 |         if(arr[mid]==k){
42 |             return mid;
43 |         }
44 |         else if(arr[mid]<k){
45 |             left=mid+1;
46 |         }
47 |         else{
48 |             right = mid-1;
49 |         }
50 |     }
51 |     return -1;
52 | }
53 | 
54 | int main()
55 | {
56 |     int n = 6;
57 | 	int arr[n] = {6, 7, 9, 5, 3, 10};
58 | 	int k = 10;
59 |     cout<<linearSearch(arr, n, k);
60 |     cout<<endl;
61 |     cout<<binarySearch(arr, n, k);
62 | 
63 |     return 0;
64 | }
65 | 


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/Striver TCS Sheet/01]. Arrays/README.md:
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1 | # Problems on Arrays


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/Striver TCS Sheet/01]. Arrays/tempCodeRunnerFile.cpp:
--------------------------------------------------------------------------------
1 | or(int i=0; i<n; i++){
2 |     //     cout<<arr[i]<<" ";
3 |     // }


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/Striver TCS Sheet/02]. Problems_on_Numbers/01_Check_if_a_number_is_Palindrome_or_Not.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Check if a number is Palindrome or Not
 3 | Problem Statement:  Given a number check if it is a palindrome.
 4 | 
 5 | An integer is considered a palindrome when it reads the same backward as forward.
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input: N = 123
11 | Output: Not Palindrome Number
12 | Explanation: 123 read backwards is 321.Since these are two different numbers 123 is not a palindrome.
13 | 
14 | Example 2:
15 | Input: N =  121 
16 | Output: Palindrome Number
17 | Explanation: 121 read backwards as 121.Since these are two same numbers 121 is a palindrome.
18 | */ 
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 | 
23 | // Method 1: 
24 | // TC: O(n)
25 | // SC: O(n)
26 | bool isPalindrome(int x){
27 |     vector<int>arr;
28 |     while(x>0){
29 |         arr.push_back(x%10);
30 |         x/=10;
31 |     }
32 | 
33 |     int n = arr.size();
34 |     int i = 0;
35 |     int j = n-1;
36 |     while(i<j){
37 |         if(arr[i]!=arr[j]){
38 |             return false;
39 |         }
40 |         i++;
41 |         j--;
42 |     }
43 |     return true;
44 | }
45 | 
46 | int main()
47 | {
48 |     int x = 1925;
49 |     cout<<boolalpha<<isPalindrome(x);
50 |     cout<<endl;
51 |     cout<<boolalpha<<isPalindrome(121);
52 | 
53 |     return 0;
54 | }
55 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/03_Check_if_a_number_is_prime_or_not.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Check if a number is prime or not
 3 | Problem Statement: Given a number, check whether it is prime or not. A prime number is a natural number that is only divisible by 1 and by itself.
 4 | 
 5 | Examples 1 2 3 5 7 11 13 17 19 …
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input: N = 3
11 | Output: Prime
12 | Explanation: 3 is a prime number
13 | 
14 | Example 2:
15 | Input: N = 26
16 | Output: Non-Prime
17 | Explanation: 26 is not prime
18 | */ 
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 | 
23 | bool isPrime(int n){
24 | 
25 |     for(int i=2; i<=n; i++){
26 |         if(n%i==0){
27 |             return false;
28 |         }
29 |     }
30 |     return true;
31 | }
32 | 
33 | int main() {
34 | 
35 |   int n = 1925;
36 | 
37 |   bool ans = isPrime(n);
38 |   if (n != 1 && ans == true) {
39 |     cout << "Prime Number";
40 |   } else {
41 |     cout << "Non Prime Number";
42 |   }
43 |   return 0;
44 | }
45 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/04_Prime_Numbers_in_a_given_range.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Prime Numbers in a given range
 3 | Problem Statement: Given a and b, find prime numbers in a given range [a,b], (a and b are included here).
 4 | 
 5 | Examples:
 6 | 
 7 | Examples:
 8 | Input: 2 10
 9 | Output: 2 3 5 7 
10 | Explanation: Prime Numbers b/w 2 and 10 are 2,3,5 and 7.
11 | 
12 | Example 2:
13 | Input: 10 16
14 | Output: 11 13 
15 | Explanation: Prime Numbers b/w 10 and 16 are 11 and 13.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void getPrimeNumbers(int a, int b){
22 |     for(int n=a; n<=b; n++){
23 |         int flag = true;
24 |         for(int j=2; j<n; j++){
25 |             if(n%j==0){
26 |                 flag = false;
27 |             }
28 |         }
29 |         if(n!=1 && flag==true)
30 |             cout<<n<<" ";
31 |     }
32 | }
33 | 
34 | int main(){
35 |     int a = 19 , b = 25;
36 |     getPrimeNumbers(a, b);
37 |     return 0;
38 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/06_Check_whether_a_number_is_Perfect_Number_or_not.cpp:
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 1 | /*
 2 | Check whether a number is Perfect Number or not
 3 | Problem Statement: Perfect Number. Write a program to find whether a number is a perfect number or not.
 4 | 
 5 | A perfect number is defined as a number that is the sum of its proper divisors ( all its positive divisors excluding itself). 
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input: n=6
11 | Output: 6 is a perfect number
12 | 
13 | Example 2:
14 | Input: n=15
15 | Output: 15 is not a perfect number
16 | 
17 | Example 3:
18 | Input: n=28
19 | Output: 28 is a perfect number
20 | Reason:
21 | For 6 and 28 , the sum of their proper divisors (1+2+3) and (1+4+7+14) is equal to the respective numbers and for 15 it is not.
22 | */ 
23 | #include<bits/stdc++.h>
24 | using namespace std;
25 | 
26 | void isPerfect(int n){
27 |     vector<int>arr;
28 |     for(int i=1; i<n; i++){
29 |         if(n%i==0){
30 |             arr.push_back(i);
31 |         }
32 |     }
33 | 
34 |     int sum = 0;
35 |     sum = accumulate(arr.begin(), arr.end(), sum);
36 |     if(sum == n){
37 |         cout<<n<<" is perfect number"<<endl;
38 |     }
39 |     else {
40 |         cout<<n<<" is not a perfect number"<<endl;
41 |     }
42 | }
43 | 
44 | int main()
45 | {
46 |     int n = 9;
47 |     isPerfect(n);
48 |     isPerfect(15);
49 |     isPerfect(28);
50 |     isPerfect(1925);
51 |     return 0;
52 | }
53 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/07_Check_whether_a_given_number_is_even_or_odd.cpp:
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 1 | /*
 2 | Check whether a given number is even or odd
 3 | Problem Statement: Given a number n, check whether a given number is even or odd.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: n=5
 9 | Output: odd
10 | Explanation: 5 is not divisible by 2.
11 |  
12 | Example 2:  
13 | Input: n=6
14 | Output: even
15 | Explanation: 6 is divisible by 2.
16 | */
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | void isOddOrEven(int n){
21 |     if(n%2==0)
22 |         cout<<n<<" is even";
23 |     else 
24 |         cout<<n<<" is odd";
25 | }
26 | 
27 | int main() {
28 |     int n = 1925;
29 |     isOddOrEven(n);
30 |   }


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/Striver TCS Sheet/02]. Problems_on_Numbers/08_Check_whether_a_number_is_positive_or_negative.cpp:
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 1 | /*
 2 | Check whether a number is positive or negative
 3 | Problem statement: Given a number n check whether it’s positive or negative.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: n=5
 9 | Output: Positive
10 | 
11 | Example2:
12 | Input: n=-6
13 | Output: Negative
14 | */ 
15 | 
16 | #include<bits/stdc++.h>
17 | using namespace std;
18 | 
19 | void check(int n){
20 |     if(n<0) cout<<n<<" is -ve"<<endl;
21 |     else cout<<n<<" is +ve"<<endl;
22 | }
23 | 
24 | int main() {
25 | 
26 | int n = 1925;
27 | check(n);
28 | n = -6;
29 | check(n);
30 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/09_Sum_of_first_N_Natural_Numbers.cpp:
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 1 | /*
 2 | Sum of first N Natural Numbers
 3 | Problem statement: Given a number ‘N’, find out the sum of the first N natural numbers.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N=5
 9 | Output: 15
10 | Explanation: 1+2+3+4+5=15
11 | 
12 | Example 2:
13 | Input: N=6
14 | Output: 21
15 | Explanation: 1+2+3+4+5+6=15
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | // TC: O(1)
22 | // SC: O(1)
23 | void getSum(int n){
24 |     int sum = n*(n+1)/2;
25 |     cout<<"The sum of first "<<n<<" natural numbers is : "<<sum<<endl;
26 | }
27 | 
28 |  int main() {
29 |     getSum(5);
30 |     getSum(19);
31 |     getSum(25);
32 |     return 0;
33 |   }


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/Striver TCS Sheet/02]. Problems_on_Numbers/12_Greatest_of_two_numbers.cpp:
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 1 | /*
 2 | Greatest of two numbers
 3 | Problem Statement: Given two numbers. Find the greatest of two numbers.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 1 3
 9 | Output: 3
10 | Explanation: Answer is 3,since 3 is greater than 1.
11 | 
12 | Input: 1.123  1.124
13 | Output: 1.124
14 | Explanation: Answer is 1.124,since 1.124 is greater than 1.123.
15 | 
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void getLargest(int a, int b){
22 |     cout<<"Greatest number is "<<max(a, b)<<endl;
23 | }
24 | int main() {
25 | 	int num1 = 19, num2= 25;
26 | 	getLargest(num1, num2);
27 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/13_Greatest_of_three_numbers.cpp:
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 1 | /*
 2 | Greatest of three numbers
 3 | Problem Statement: Given three numbers. Find the greatest of three numbers.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 1 3 5
 9 | Output: 5
10 | Explanation: Answer is 5.Since 5 is greater than 1 and 3.
11 | 
12 | Example 2:
13 | Input: 1.123  1.124 1.125
14 | Output: 1.125
15 | Explanation: Answer is 1.125. Since 1.125 is greater than 1.123 and 1.124
16 | */ 
17 | 
18 | #include<iostream>
19 | using namespace std;
20 | 
21 | void getLargest(double a, double b, double c){
22 |     double sec_largest = max(a, b);
23 |     double largest = max(c, sec_largest);
24 |     cout<<"Largest number is "<<largest<<endl;
25 | }
26 | 
27 | int main()
28 | {
29 |     double num1 = 19.25, num2= 25.19, num3 = 71.10;
30 |     getLargest(num1, num2, num3);
31 |     return 0;
32 | }
33 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/15_Reverse_digits_of_a_number.cpp:
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 1 | /*
 2 | Reverse digits of a number
 3 | Problem Statement: Given an integer. Write a program to reverse digits of a number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 472
 9 | Output: 274
10 | Explanation: Reading the number from back to front, we see that the output should be 274
11 | 
12 | Example 2:
13 | Input: N = 470
14 | Output: 74
15 | Explanation: Reading the number from back to front, we get 074. For an integer with no decimals, we know that leading zeros have no significance and therefore our answer should be 74
16 | */ 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | int reverseDigits(int num){
21 |     vector<int>arr;
22 |     int res=0;
23 |     while(num>0){
24 |         arr.push_back(num%10);
25 |         num/=10;
26 |     }
27 | 
28 |     for(int i=0; i<arr.size(); i++){
29 |         res = res*10 + arr[i];
30 |     }
31 |     cout<<endl;
32 |     return res;
33 | 
34 | }
35 | 
36 | int main(){
37 |     int num = 1925;
38 | 
39 |     cout<<reverseDigits(num);
40 |     int num2 = 470;
41 |     cout<<reverseDigits(num2);
42 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/16_Maximum_and_Minimum_digit_in_a_number.cpp:
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 1 | /*
 2 | Maximum and Minimum Digit in a Number
 3 | Problem Statement: Given a number N, print the smallest and largest digits present in the number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 2746
 9 | Output: Largest digit: 7
10 |         Smallest digit: 2
11 | Explanation: By simply going through the digits of 
12 | the number, we figure out the largest and smallest 
13 | digit in the number.
14 | 
15 | Example 2:
16 | Input: N = 23004
17 | Output: Largest digit : 4
18 |         Smallest digit : 0
19 | Explanation: By simply going through the digits of 
20 | the number, we figure out the largest and smallest 
21 | digit in the number.
22 | */ 
23 | 
24 | #include<bits/stdc++.h>
25 | using namespace std;
26 | 
27 | void get_max_and_min_digit(int num){
28 |     vector<int>arr;
29 |     while(num>0){
30 |         arr.push_back(num%10);
31 |         num/=10;
32 |     }
33 |     sort(arr.begin(), arr.end());
34 |     cout<<"Smallest Digit: "<<arr[0]<<endl<<"Largest Digit: "<<arr[arr.size()-1]<<endl;
35 | }
36 | 
37 | int main(){
38 |     int num = 1925;
39 |     get_max_and_min_digit(num);
40 |     return 0;
41 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/17_Print_Fibonacci_Series_up_to_Nth_term.cpp:
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 1 | /*
 2 | Print Fibonacci Series up to Nth term
 3 | Problem Statement: Given an integer N. Print the Fibonacci series up to the Nth term.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5
 9 | Output: 0 1 1 2 3 5
10 | Explanation: 0 1 1 2 3 5 is the fibonacci series up to 5th term.(0 based indexing)
11 | 
12 | Example 2:
13 | Input: 6
14 | Output: 0 1 1 2 3 5 8
15 | Explanation: 0 1 1 2 3 5 8 is the fibonacci series upto 6th term.(o based indexing)
16 | 
17 | */ 
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | void getFibonacci(int n){
23 |    
24 |    
25 | }
26 | 
27 | int main()
28 | {
29 |     int n = 6;
30 |     getFibonacci(n);
31 |     return 0;
32 | }
33 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/18_Factorial_of_a_Number.cpp:
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 1 | /*
 2 | Factorial of a Number : Iterative and Recursive
 3 | Problem Statement: Given a number X,  print its factorial.
 4 | 
 5 | To obtain the factorial of a number, it has to be multiplied by all the whole numbers preceding it. More precisely X! = X*(X-1)*(X-2) … 1.
 6 | 
 7 | Note: X  is always a positive number. 
 8 | 
 9 | Examples:
10 | 
11 | Example 1:
12 | Input: X = 5
13 | Output: 120
14 | Explanation: 5! = 5*4*3*2*1
15 | 
16 | Example 2:
17 | Input: X = 3
18 | Output: 6
19 | Explanation: 3!=3*2*1
20 | */ 
21 | 
22 | #include<bits/stdc++.h>
23 | using namespace std;
24 | 
25 | void getFactorial(int n){
26 |     int res=1;
27 |     for(int i=1; i<=n; i++){
28 |         res*=i;
29 |     }
30 |     cout<<"Factoral of "<<n<<" is "<<res<<endl;
31 | }
32 | 
33 | 
34 | int main()
35 | {
36 |     int n = 5;
37 |     getFactorial(n);
38 |     getFactorial(3);
39 |     return 0;
40 | }
41 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/19_Calculate_the_Power_of_a_Number.cpp:
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 1 | /*
 2 | Calculate the Power of a Number : Binary Exponentiation
 3 | Problem Statement: Find the Power of a number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5, k=3
 9 | Output: 125
10 | Explanation: Since 5*5*5 is 125.
11 | 
12 | Example 2:
13 | Input: n=2 k=4
14 | Output: 16
15 | Explanation: Since 2*2*2*2 is 16
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void powerOf(int n, int k){
22 |     int res=1;
23 |     for(int i=0; i<k; i++){
24 |         res*=n;
25 |     }
26 |     cout<<"Power of "<<n<<" to "<<k<<" is "<<res<<endl;
27 | }
28 | 
29 | int main()
30 | {
31 |     int n = 5, k = 3;
32 |     powerOf(n, k);
33 |     powerOf(2, 4);
34 |     return 0;
35 | }
36 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/21_Print_all_Prime_Factors_of_the_given_number.cpp:
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 1 | /*
 2 | Print all Prime Factors of the given number
 3 | Problem Statement: Given a number n. Print all Prime Factors of the given number n.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 12
 9 | Output: 2,2,3
10 | Explanation: These are the prime factors of 12.
11 | 
12 | Example 2:
13 | Input: N = 36
14 | Output: 2,2,3,3
15 | Explanation: These are the prime factors of 36.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void getPrimeFactors(int n){
22 |     vector<int>arr;
23 |     for(int i=1; i<n; i++){
24 |         if(n%i==0){
25 |             arr.push_back(i);
26 |         }
27 |     }
28 | 
29 |     for(int i=0; i<arr.size(); i++){
30 |         int flag = true;
31 |         for(int j=2; j<arr[i]; j++){
32 |             if(arr[i]%j==0){
33 |                 flag = false;
34 |             }
35 |         }
36 |         if(arr[i]!=1 && flag==true){
37 |             cout<<arr[i]<<" ";
38 |         }
39 |     }
40 | }
41 | 
42 | int main()
43 | {
44 |     int n = 12;
45 |     getPrimeFactors(n);
46 |     return 0;
47 | }
48 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/22_Check_if_a_number_is_a_Strong_Number_or_not.cpp:
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 1 | /*
 2 | Check if a number is a Strong Number or not
 3 | Problem Statement: Given an integer Print “YES” if it is a strong number else print “NO”.
 4 | 
 5 | Note : 
 6 | 
 7 | When the sum of factorial of individual digits of a number is equal to the original number the number is called a strong number. 
 8 | Strong number is also known as Krishnamurthi number/Peterson Number.
 9 | Examples:
10 | 
11 | Examples 1:
12 | Input: N = 145
13 | Output: Yes
14 | Explanation: 1! + 4! + 5! = 145. Hence 145 is a strong number. 
15 | 
16 | Example 2:
17 | Input:  26
18 | Output: No
19 | Explanation: 2! + 6! = 722. Hence 26 is not a strong number.
20 | */ 
21 | 
22 | #include<bits/stdc++.h>
23 | using namespace std;
24 | 
25 | int factorial(int n){
26 |     int fact = 1;
27 |     for(int i=1; i<=n; i++){
28 |         fact *= i;
29 |     }
30 |     return fact;
31 | }
32 | 
33 | void isStrong(int n){
34 |     int res = 0;
35 |     vector<int>arr;
36 |     int temp = n;
37 |     while(temp>0){
38 |         arr.push_back(temp%10);
39 |         temp/=10;
40 |     }
41 | 
42 |     for(int i=0; i<arr.size(); i++){
43 |         res += factorial(arr[i]);
44 |     }
45 | 
46 |     if(res == n){
47 |         cout<<"Yes"<<endl;
48 |     }
49 |     else{
50 |         cout<<"No"<<endl;
51 |     }
52 | }
53 | 
54 | int main()
55 | {
56 |     int n= 145;
57 |     
58 |     isStrong(n);
59 |     isStrong(26);
60 |     isStrong(1925);
61 |     return 0;
62 | }
63 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/26_Check_if_the_given_number_is_Harsha_Or_Niven_Number.cpp:
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 1 | /*
 2 | Check if the given number is Harshad(Or Niven) Number
 3 | Problem Statement: Check if the number is a Harshad(or Niven) number or not.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 378
 9 | Output: Yes it is a Harshad number.
10 | Explanation: 3+7+8=18. 378 is divisible by 18. Therefore 378 is a harshad number.
11 | 
12 | Example 2:
13 | Input: 379
14 | Output: No
15 |  it is not a Harshad number.
16 | Explanation: 3+7+9=19. 379 is not divisible by 19. Therefore 379 is a harshad number.
17 | */ 
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | void isNiven(int n){
23 |     vector<int>arr;
24 |     int temp = n;
25 |     while(temp>0){
26 |         arr.push_back(temp%10);
27 |         temp /= 10;
28 |     }
29 |     int sum = 0;
30 |     sum = accumulate(arr.begin(), arr.end(), sum);
31 | 
32 |     if(n%sum==0){
33 |         cout<<n<<" Yes it is a Harshad number."<<endl;
34 |     }
35 |     else{
36 |         cout<<n<<" No, it is not a Harshad number."<<endl;
37 |     }
38 | }
39 | 
40 | int main()
41 | {
42 |     int n = 378;
43 | 
44 |     isNiven(n);
45 |     isNiven(389);
46 |     isNiven(1925);
47 |     return 0;
48 | }
49 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/02]. Problems_on_Numbers/27_Check_if_the_number_is_an_abundant_number_or_not.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Check if the number is an abundant number or not
 3 | Problem Statement: Check if the number is an abundant number or not.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 18
 9 | Output: Abundant Number
10 | Explanation: Divisors of 18 are 1,2,3,6,9. 1+2+3+6+9=21, Since 21 is greater than 18, 18 is an abundant number.
11 | 
12 | Example 2:
13 | Input: 21
14 | Output: Not Abundant Number
15 | Explanation:Divisors of 21 are 1,3,7. 1+3+7=11, Since 11 is smaller than 21, 11 is not an abundant number.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void isAbundant(int n){
22 |     vector<int>arr;
23 |     int temp = n;
24 |     for(int i=1; i<n; i++){
25 |         if(n%i==0){
26 |             arr.push_back(i);
27 |         }
28 |     }
29 |     int sum = 0;
30 |     sum = accumulate(arr.begin(), arr.end(), sum);
31 | 
32 |     if(sum > n){
33 |         cout<<n<<" is a Abundant Number"<<endl;
34 |     }
35 |     else{
36 |         cout<<n<<" is not Abundant Number"<<endl;
37 |     }
38 | 
39 | }
40 | 
41 | int main(){
42 |     int n = 18;
43 |     isAbundant(n);
44 |     isAbundant(21);
45 |     isAbundant(1925);
46 | }


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/Striver TCS Sheet/02]. Problems_on_Numbers/28_Sum_Of_Digits_of_A_Number.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Sum Of Digits of A Number
 3 | Problem Statement: Given an integer, find the sum of digits of that integer.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 472
 9 | Output: 13
10 | Explanation: The digits in the number are 4,7 and 2. Summing them up gives us a value of 13
11 | 
12 | Example 2:
13 | Input: N = 102
14 | Output: 3
15 | Explanation: The digits in the number are 0, 1, and 2. Summing them up gives us a value of 3
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void getSumOfDigits(int num){
22 |     vector<int>arr;
23 |     int sum = 0;
24 |     while(num>0){
25 |         arr.push_back(num%10);
26 |         num/=10;
27 |     }
28 |     cout<<accumulate(arr.begin(), arr.end(), sum)<<endl;
29 | }
30 | 
31 | int main()
32 | {
33 |     int num = 1925;
34 |     getSumOfDigits(num);
35 |     getSumOfDigits(9999);
36 | 
37 |     return 0;
38 | }
39 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/29_Find_the_sum_of_numbers_in_the_given_range.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find the sum of numbers in the given range
 3 | Problem Statement: Find the sum of numbers in the given range.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: l=2, r=7
 9 | Output: 27
10 | Explanation: 2+3+4+5+6+7=27. Therefore 27 is the answer.
11 | 
12 | Example 2:
13 | Input: l=5, r=9
14 | Output: 35
15 | Explanation: 5+6+7+8+9=35. Therefore 35 is the answer.
16 | */ 
17 | #include<iostream>
18 | using namespace std;
19 | 
20 | void getSum(int l, int r){
21 |     int sum = 0;
22 |     for(int i=l; i<=r; i++){
23 |         sum += i;
24 |     }
25 |     cout<<"sum : "<<sum<<endl;
26 | }
27 | 
28 | int main()
29 | {
30 |     int l = 2, r = 7;
31 |     getSum(l, r);
32 | 
33 |     getSum(5, 9);
34 |     getSum(19, 25);
35 |     return 0;
36 | }
37 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/32_Replace_all_the_0s_with_1_in_a_given_integer.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Replace all the 0’s with 1 in a given integer
 3 | Problem Statement: You are given an integer. Your task is to replace all the zeros in the integer with ones.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 102003
 9 | Output: 112113
10 | Explanation: The 2nd,4th and 5th position from left contain 0.The resultant integer has replaced the 0’s in those  positions with 1.
11 | 
12 | Example 2:
13 | Input:  204
14 | Output: 214
15 | Explanation: The 2nd position from left contain 0. The resultant integer has replaced the 0 in that position with 1.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void replaceZerosWithOne(int n){
22 |     vector<int>arr;
23 |     int res = 0;
24 |     while(n>0){
25 |         arr.push_back(n%10);
26 |         n/=10;
27 |     }
28 | 
29 |     reverse(arr.begin(), arr.end());
30 | 
31 |     for(int i=0; i<arr.size(); i++){
32 |         if(arr[i]==0){
33 |             arr[i]=1;
34 |         }
35 |     }
36 | 
37 |     for(int i=0; i<arr.size(); i++){
38 |         res = res*10 + arr[i];
39 |     }
40 |     cout<<res<<endl;
41 | }
42 | 
43 | int main()
44 | {
45 |     int n = 204;
46 |     replaceZerosWithOne(n);
47 |     replaceZerosWithOne(102003);
48 |     return 0;
49 | }
50 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/33_Express_given_number_as_Sum_of_Two_Prime_Numbers.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Express given number as Sum of Two Prime Numbers
 3 | Problem: Given a number n, express the number as a sum of 2 prime numbers.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input : N = 74
 9 | Output : True . 
10 | Explanation: 74 can be expressed as 71 + 3 and both are prime numbers. 
11 | 
12 | Example 2:
13 | Input : N = 11
14 | Output : False. 
15 | Explanation: 11 cannot be expressed as sum of two prime numbers.
16 | */ 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | bool isSumOfTwoPrime(int n){
21 |     vector<int>arr;
22 |     for(int num=1; num<n; num++){
23 |         int flag = true;
24 |         for(int j=2; j<num; j++){
25 |             if(num%j==0){
26 |                 flag = false;
27 |             }
28 |         }
29 |         if(num!=1 && flag==true){
30 |             arr.push_back(num);
31 |         }
32 |     }
33 | 
34 |     for(auto x: arr) cout<<x<<" ";
35 | 
36 |     for(int i=0; i<n; i++){
37 |         for(int j=i+1; j<n; j++){
38 |             if(arr[i]+arr[j]==n){
39 |                 return true;
40 |             }
41 |         }
42 |     }
43 |     return false;
44 | }
45 | 
46 | int main()
47 | {
48 |     int n = 11;
49 |     cout<<boolalpha<<isSumOfTwoPrime(n)<<endl;
50 |     cout<<boolalpha<<isSumOfTwoPrime(74)<<endl;
51 |     return 0;
52 | }
53 | 


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/Striver TCS Sheet/02]. Problems_on_Numbers/34_Calculate_the_Area_of_the_Circle.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Calculate the Area of the Circle
 3 | Problem Statement: Given the radius of the circle, calculate the area of the circle.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 5
 9 | Output: 78.5
10 | Explanation: Using formula  πr2 for finding area of circle we get area as 78.5
11 | 
12 | Example 2:
13 | Input: N = 4
14 | Output: 50.2
15 | Explanation: Using formula  πr2 for finding area of circle we get area as 50.2
16 | */ 
17 | 
18 | #include<iostream>
19 | using namespace std;
20 | 
21 | double getAreaOfCircle(double r){
22 |     return 3.14*r*r;
23 | }
24 | 
25 | int main()
26 | {
27 |     int r = 5;
28 |     cout<<getAreaOfCircle(r)<<endl;
29 |     cout<<getAreaOfCircle(4)<<endl;
30 |     return 0;
31 | }
32 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/02]. Problems_on_Numbers/README.md:
--------------------------------------------------------------------------------
1 | # Problems On Numbers


--------------------------------------------------------------------------------
/Striver TCS Sheet/02]. Problems_on_Numbers/tempCodeRunnerFile.cpp:
--------------------------------------------------------------------------------
1 | ndl;
2 | 
3 |     // cout<<boolalpha<<isSumOfTwoPrime(74)<<e


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/Striver TCS Sheet/03]. Problems_on_Number_System/01_Convert_Binary_to_Decimal.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Binary to Decimal
 3 | Problem Statement: Convert a binary number to a decimal number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 1011
 9 | Output: 11
10 | Explanation: 1011 when converted to decimal number is “11”.
11 | 
12 | Example 2:
13 | Input: 100
14 | Output: 4
15 | Explanation: 100 when converted to decimal number is “4”.
16 | */ 
17 | #include<iostream>
18 | #include<vector>
19 | #include<cmath>
20 | #include<string>
21 | using namespace std;
22 | 
23 | // Method 1: 
24 | // TC: O(n) n = No. of Digits in the number
25 | // SC: O(n) n = No. of Digits in the number
26 | int convert_to_decimal1(int N){
27 |     vector<int>v;
28 |     int res = 0;
29 |     while(N>0){
30 |         v.push_back(N%10);
31 |         N /= 10;
32 |     }
33 | 
34 |     for(int i=0; i<v.size(); i++){
35 |         if(v[i]==1){
36 |             res += pow(2, i);
37 |         }
38 |     }
39 |     return res;
40 | }
41 | 
42 | int convert_to_decimal2(string M){
43 |     int res = 0;
44 |     int base = 1;
45 |     int n = M.length();
46 |     for(int i=n-1; i>=0; i--){
47 |         if(M[i] == '1')
48 |             res += base;
49 |         base *= 2;
50 |     }
51 |     return res;
52 | }
53 | 
54 | 
55 | int main(){
56 |     int N = 1011;
57 |     cout<<convert_to_decimal1(N)<<endl;
58 | 
59 |     // Method 2: 
60 |     // Get the input in the string formal 
61 |     string M = "1011";
62 |     cout<<convert_to_decimal2(M);
63 |     return 0;
64 | }
65 | 


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/Striver TCS Sheet/03]. Problems_on_Number_System/02_Binary_Number_to_Octal_Number.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Binary to Octal
 3 | Problem Statement: Convert a binary number to an octal number
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:.
 8 | Input: N = 1100110
 9 | Output: 146
10 | Explanation: 1100110 when converted to octal number is “146”.
11 | 
12 | Example 2:
13 | Input: 11111
14 | Output: 37
15 | Explanation: 11111 when converted to octal number is “37”.
16 | */ 
17 | 
18 | #include<iostream>
19 | #include<string>
20 | using namespace std;
21 | 
22 | void convert_binary_to_octal(string s){
23 |     int n = s.length();
24 |     if( n%3 == 1){
25 |         s = "00" + s;
26 |     }
27 |     else if( n%3 == 2){
28 |         s = "0" + s;
29 |     }
30 |     n = s.length();
31 |     string res = "";
32 |     for(int i = 0; i < n; i += 3){
33 |         // converting to int by substracting '0' before multiplying
34 |         int temp = (s[i]-'0')*4 + (s[i+1]-'0')*2 + (s[i+2]-'0')*1; 
35 |         // converting to string again by adding '0' and adding it to the res
36 |         res += temp + '0'; 
37 |     }
38 |     cout<<res;
39 | }
40 | 
41 | int main(){
42 |     string s = "1100110";
43 |     convert_binary_to_octal(s); 
44 | } 


--------------------------------------------------------------------------------
/Striver TCS Sheet/03]. Problems_on_Number_System/03_Convert_Decimal_to_Binary_Number.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Decimal to Binary Number
 3 | Problem Statement: Convert decimal to binary number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 15
 9 | Output: 1111
10 | Explanation: 15 in binary is represented as "1111".
11 | 
12 | Example 2:
13 | Input: 18
14 | Output: 10010
15 | Explanation: 18 in binary is represented as "10010".
16 | */ 
17 | 
18 | #include<iostream>
19 | using namespace std;
20 | 
21 | void decimal_to_binary(int n){
22 |     int binary[32] = {0};
23 |     int i = 0;
24 |     while(n){
25 |         binary[i] = n%2;
26 |         i++;
27 |         n /= 2;
28 |     }
29 |     
30 |     int res = 0;
31 |     for(int ind = i-1; ind>=0; ind--){
32 |         cout<<binary[ind];
33 |     }
34 | }
35 | 
36 | int main(){
37 |     int n = 28;
38 |     decimal_to_binary(n);
39 |     return 0;
40 | }


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/Striver TCS Sheet/03]. Problems_on_Number_System/04_Decimal_to_octal_conversion.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Decimal to Octal
 3 | Problem Statement: Given a decimal number, convert it into Octal Number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input:  17
 9 | Output: 21
10 | Explanation: Octal Equivalent of 17 is 21
11 | 
12 | Example 2:
13 | Input:  45
14 | Output: 55
15 | Explanation: Octal Equivalent of 45 is 55
16 | */ 
17 | 
18 | #include<iostream>
19 | #include<math.h>
20 | using namespace std;
21 | 
22 | int decimal_to_octal(int decimal){
23 |     int octal = 0;
24 |     int i = 0;
25 |     while(decimal != 0){
26 |         int rem = decimal % 8;
27 |         octal += rem * pow(10, i);
28 |         i++; 
29 |         decimal = decimal / 8;
30 |     }
31 |     return octal;
32 | }
33 | 
34 | int main(){
35 |     int decimal = 136;
36 |     cout<<decimal_to_octal(decimal);
37 |     return 0;
38 | }


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/Striver TCS Sheet/03]. Problems_on_Number_System/05_Octal_to_Binary_numbers.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Octal to Binary
 3 | Problem Statement: Given an Octal Number, convert it into Binary Number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 345
 9 | Output: 011100101
10 | Explanation: Binary equivalent of given Octal expressionis 011100101
11 | 
12 | Example 2:
13 | Input: 170
14 | Output: 001111000
15 | Explanation: Binary equivalent of given Octal expression is 001111000
16 | */ 
17 | 
18 | #include<iostream>
19 | #include<math.h>
20 | using namespace std;
21 | 
22 | int convert_octal_to_decimal(int octal){
23 |     int decimal = 0;
24 |     int i = 0;
25 |     while(octal > 0){
26 |         int rem = octal % 10;
27 |         decimal += rem * pow(8, i);
28 |         i++;
29 |         octal = octal / 10;
30 |     }
31 |     return decimal;
32 | }
33 | 
34 | int convert_octal_to_binary(int octal){
35 |     int decimal = convert_octal_to_decimal(octal);
36 |     int binary = 0;
37 |     int i = 0;
38 |     while(decimal != 0){
39 |         int rem = decimal % 2;
40 |         binary += (rem * pow(10, i));
41 |         i++;
42 |         decimal = decimal / 2;
43 |     } 
44 |     return binary;
45 | }
46 | 
47 | int main(){
48 |     int octal = 345;
49 |     cout<<convert_octal_to_binary(octal);
50 |     return 0;
51 | }


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/Striver TCS Sheet/03]. Problems_on_Number_System/06_Octal_to_decimal.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Convert Octal to Decimal
 3 | Problem Statement: Given an Octal Number, convert it into a Decimal Number.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: 345
 9 | Output: 229
10 | Explanation: Decimal equivalent of given Octal expressionis 229
11 | 
12 | Example 2:
13 | Input: 170
14 | Output: 121
15 | Explanation: Decimal equivalent of given Octal expression is121
16 | */ 
17 | 
18 | #include<iostream>
19 | #include<math.h>
20 | using namespace std;
21 | 
22 | int convert_octal_to_decimal(int octal){
23 |     int decimal = 0;
24 |     int i = 0;
25 |     while(octal != 0){
26 |         int rem = octal % 10;
27 |         decimal += rem * pow(8, i);
28 |         i++;
29 |         octal = octal / 10;
30 |     }
31 |     return decimal;
32 | }
33 | 
34 | int main(){
35 |     int octal = 345;
36 |     cout<<convert_octal_to_decimal(octal);
37 |     return 0;
38 | }


--------------------------------------------------------------------------------
/Striver TCS Sheet/03]. Problems_on_Number_System/README.md:
--------------------------------------------------------------------------------
1 | # Problems on Number System


--------------------------------------------------------------------------------
/Striver TCS Sheet/03]. Problems_on_Number_System/tempCodeRunnerFile.cpp:
--------------------------------------------------------------------------------
1 | 345


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/Striver TCS Sheet/04]. Problems_on_Sorting/01_Bubble_Sort.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Bubble Sort Algorithm
 3 | Problem Statement: Given an array of N integers, write a program to implement the Bubble Sorting algorithm.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 6, array[] = {13,46,24,52,20,9}
 9 | Output: 9,13,20,24,46,52
10 | Explanation: After sorting we get 9,13,20,24,46,52
11 | 
12 | 
13 | Input: N = 5, array[] = {5,4,3,2,1}
14 | Output: 1,2,3,4,5
15 | Explanation: After sorting we get 1,2,3,4,5
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | // Worst Case TC: O(n*n)
22 | // Best case TC: O(n) : if array is already sorted
23 | // Bubble Sort is Adaptive, we can make it adaptive - By nature Bubble sort is not adaptive
24 | // Bubble Sort is Stable
25 | void BubbleSort(int A[], int n){
26 |     for(int i=0; i<n-1; i++){
27 |         bool flag = 0;
28 |         for(int j=0; j<n-1-i; j++){
29 |             if(A[j] > A[j+1]){
30 |                 swap(A[j], A[j+1]);
31 |                 flag = 1;
32 |             }
33 |         }
34 |         if(flag == 0){
35 |             break;
36 |         }
37 |     }
38 | }
39 | 
40 | int main()
41 | {
42 |     int A[]={13,46,24,52,20,9};
43 | 
44 |     cout<<"Before Sorting: "<<endl;
45 |     for(auto x: A){
46 |         cout<<x<<" ";
47 |     }
48 |     cout<<endl;
49 |     int n = sizeof(A)/sizeof(A[0]);
50 |     BubbleSort(A, n);
51 | 
52 |     cout<<"After Sorting: "<<endl;
53 |     for(auto x: A){
54 |         cout<<x<<" ";
55 |     }
56 |     return 0;
57 | }


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/Striver TCS Sheet/04]. Problems_on_Sorting/02_Insertion_Sort.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Insertion Sort Algorithm
 3 | Problem Statement: Given an array of N integers, write a program to implement the Insertion sorting algorithm.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 6, array[] = {13,46,24,52,20,9}
 9 | Output: 9,13,20,24,46,52
10 | Explanation: 
11 | After sorting the array is: 9,13,20,24,46,52
12 | 
13 | 
14 | Example 2:
15 | Input: N=5, array[] = {5,4,3,2,1}
16 | Output: 1,2,3,4,5
17 | Explanation: After sorting the array is: 1,2,3,4,5
18 | */ 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | // Worst case TC: O(n*n)
23 | // Best case TC: O(n)
24 | // Insertion sort is Adaptive in nature
25 | // Insertion sort is stable
26 | void InsertionSort(int arr[], int n){
27 |     for(int i=1; i<n; i++){
28 |         int j=i-1;
29 |         int x = arr[i];
30 |         while(j>=0 && arr[j]>x){
31 |             arr[j+1]=arr[j];
32 |             j--;
33 |         }
34 |         arr[j+1]=x; 
35 |     }
36 | }
37 | 
38 | int main()
39 | {
40 |     int arr[] = {13,46,24,52,20,9};
41 |     int n = sizeof(arr)/sizeof(arr[0]);
42 | 
43 |     cout<<"Before Sorting: "<<endl;
44 |     for(auto x: arr){
45 |         cout<<x<<" ";
46 |     }
47 |     cout<<endl;
48 |     InsertionSort(arr, n);
49 | 
50 |     cout<<"After Sorting: "<<endl;
51 |     for(auto x: arr){
52 |         cout<<x<<" ";
53 |     }
54 |     return 0;
55 | }
56 | 
57 | 


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/Striver TCS Sheet/04]. Problems_on_Sorting/03_Selection_Sort.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Selection Sort Algorithm
 3 | Problem Statement: Given an array of N integers, write a program to implement the Selection sorting algorithm.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N = 6, array[] = {13,46,24,52,20,9}
 9 | Output: 9,13,20,24,46,52
10 | Explanation: After sorting the array is: 9, 13, 20, 24, 46, 52
11 | 
12 | Example 2:
13 | Input: N=5, array[] = {5,4,3,2,1}
14 | Output: 1,2,3,4,5
15 | Explanation: After sorting the array is: 1, 2, 3, 4, 5
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void selectionSort(int arr[], int n){
22 |     int i,j,k;
23 |     for(i=0; i<n-1; i++){
24 |         for(j=k=i; j<n; j++ ){
25 |             if(arr[j]<arr[k]){
26 |                 k=j;
27 |             }
28 |         }
29 |         swap(arr[i], arr[k]);
30 |     }
31 | }
32 | 
33 | int main()
34 | {
35 |     int arr[] = {8,6,3,10,9,8,12,5,2,7};
36 |     int n = sizeof(arr)/sizeof(arr[0]);
37 | 
38 |     cout<<"Before Sorting: "<<endl;
39 |     for(auto x: arr){
40 |         cout<<x<<" ";
41 |     }
42 |     cout<<endl;
43 |     selectionSort(arr, n);
44 | 
45 |     cout<<"After Sorting: "<<endl;
46 |     for(auto x: arr){
47 |         cout<<x<<" ";
48 |     }
49 |     return 0;
50 | }


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/Striver TCS Sheet/04]. Problems_on_Sorting/04_Quick_Sort.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Quick Sort Algorithm
 3 | Problem Statement:  Given an array of n integers, sort the array using the Quicksort method.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input:  N = 5  , Arr[] = {4,1,7,9,3}
 9 | Output: 1 3 4 7 9 
10 | 
11 | Explanation: After sorting the array becomes 1, 3, 4, 7, 9
12 | 
13 | Example 2:
14 | Input: N = 8 , Arr[] = {4,6,2,5,7,9,1,3}
15 | Output: 1 2 3 4 5 6 7 9
16 | Explanation: After sorting the array becomes 1, 3, 4, 7, 9
17 | */ 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | int swap(int arr[], int i, int j){
22 |     int temp = arr[i];
23 |     arr[i]=arr[j];
24 |     arr[j]=temp;
25 | }
26 | 
27 | int partition(int arr[], int l, int r){
28 |     int pivot=arr[r];
29 |     int i=l-1;
30 | 
31 |     for(int j=l; j<r; j++){
32 |         if(arr[j]<pivot){
33 |             i++;
34 |             swap(arr, i, j);
35 |         }
36 |     }
37 |     swap(arr, i+1, r);
38 |     return i+1;
39 | }
40 | 
41 | void quickSort(int arr[], int l, int r){
42 |     if(l<r){
43 |         int pi = partition(arr, l, r);
44 |         quickSort(arr, l, pi-1);
45 |         quickSort(arr, pi+1, r);
46 | 
47 |     }
48 | }
49 | 
50 | int main()
51 | {
52 |     int arr[5]={5,4,3,2,1};
53 |     quickSort(arr, 0, 4);
54 | 
55 |     for(int i=0; i<5; i++){
56 |         cout<<arr[i]<<" ";
57 |     }
58 |     return 0;
59 | }
60 | 


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/Striver TCS Sheet/04]. Problems_on_Sorting/05_Merge_Sort.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Merge Sort Algorithm
 3 | Problem:  Given an array of size n, sort the array using Merge Sort.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: N=5, arr[]={4,2,1,6,7}
 9 | Output: 1,2,4,6,7,
10 | 
11 | 
12 | Example 2:
13 | Input: N=7,arr[]={3,2,8,5,1,4,23}
14 | Output: 1,2,3,4,5,8,23
15 | */
16 | #include<iostream>
17 | using namespace std;
18 | 
19 | void merge(int arr[], int l, int mid, int r){
20 |     int n1=mid-l+1;
21 |     int n2=r-mid;
22 | 
23 |     int a[n1];
24 |     int b[n2];
25 | 
26 |     for(int i=0; i<n1; i++){
27 |         a[i]=arr[l+i];
28 |     }
29 |     for(int i=0; i<n2; i++){
30 |         b[i]=arr[mid+1+i];
31 |     }
32 |     int i=0; int j=0;
33 |     int k=l;
34 |     while(i<n1 && j<n2){
35 |         if(a[i]<b[j]){
36 |             arr[k]=a[i];
37 |             k++;
38 |             j++;
39 |         }
40 |         else
41 |         {
42 |             arr[k]=b[j];
43 |             k++; 
44 |             j++;
45 |         }
46 |     }
47 | 
48 |     while(i<n1){
49 |         arr[k]=a[i];
50 |         k++; 
51 |         i++;
52 |     }
53 | 
54 |     while(j<n2){
55 |         arr[k]=b[j];
56 |         k++;
57 |         j++;
58 |     }
59 | }
60 | 
61 | void mergeSort(int arr[], int l, int r){
62 |     if(l<r){
63 |         int mid=(l+r)/2;
64 |         mergeSort(arr, l, mid);
65 |         mergeSort(arr, mid+1, r);
66 | 
67 |         merge(arr, l, mid, r);
68 |     }
69 | }
70 | 
71 | int main()
72 | {
73 |     int arr[]={5,4,3,2,1};
74 |     mergeSort(arr, 0, 4);
75 | 
76 |     for(int i=0; i<5; i++){
77 |         cout<<arr[i]<<" ";
78 |     }
79 |     return 0;
80 | }
81 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/04]. Problems_on_Sorting/README.md:
--------------------------------------------------------------------------------
1 | # Problems on Sorting


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/01_Check_if_the_given_String_is_Palindrome_or_not.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Check if the given String is Palindrome or not
 3 | Problem Statement: “Given a string, check if the string is palindrome or not.”  A string is said to be palindrome if the reverse of the string is the same as the string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: Str =  “ABCDCBA”
 9 | Output: Palindrome
10 | Explanation: String when reversed is the same as string.
11 | 
12 | Example 2:
13 | Input: Str = “TAKE U FORWARD”
14 | Output: Not Palindrome
15 | Explanation: String when reversed is not the same as string.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | bool isPalindrome(string str){
22 |     int i = 0;
23 |     int j = str.length()-1;
24 | 
25 |     while(i<j){
26 |         if(str[i]!=str[j]){
27 |             return false;
28 |         }
29 |         i++;
30 |         j--;
31 |     }
32 |     return true;
33 | }
34 | 
35 | int main()
36 | {
37 |     string str = "MADAM";
38 |     cout<<boolalpha<<isPalindrome(str);
39 |     return 0;
40 | }
41 | 


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/Striver TCS Sheet/05]. Problems_on_String/02_Count_number_of_vowels_and_consonants_and_spaces_in_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Count number of vowels, consonants, spaces in String
 3 | Problem Statement: Given a string, write a program to count the number of vowels, consonants, and spaces in that string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: string str=”Take u forward is Awesome”
 9 | Output: 
10 | Vowels: 10
11 | Consonants: 11
12 | White spaces: 4
13 | Explanation: 
14 | 
15 | Example 2:
16 | Input: string str=”India won the cricket match”
17 | Output:
18 | Vowels: 8
19 | Consonants: 15
20 | White spaces: 4
21 | */ 
22 | 
23 | #include<iostream>
24 | using namespace std;
25 | 
26 | void solve(string str, int n){
27 |     int count_v = 0;
28 |     int count_c = 0;
29 |     int count_s = 0;
30 | 
31 |     for(int i=0; i<n; i++){
32 |         if(str[i]=='a' || str[i]=='e' || str[i]=='i' || str[i]=='o' || str[i]=='u' ||
33 |            str[i]=='A' || str[i]=='E' || str[i]=='I' || str[i]=='O' || str[i]=='U'){
34 |             count_v++;
35 |             cout<<str[i]<<" ";
36 |         }
37 |         else if(str[i]!=' '){
38 |             count_c++;
39 |             // cout<<str[i]<<" ";
40 | 
41 |         }
42 | 
43 |         if(str[i]==' '){
44 |             count_s++;
45 |             // cout<<str[i]<<" ";
46 |         }
47 |     }
48 |     cout<<endl<<endl;
49 | 
50 |     cout<<"Vowels: "<<count_v<<endl;
51 |     cout<<"Consonents: "<<count_c<<endl;
52 |     cout<<"Spaces: "<<count_s<<endl;
53 | 
54 | }
55 | 
56 | int main()
57 | {
58 |     string str = "India won the cricket match";
59 |     int length = str.length();
60 |     solve(str, length);
61 | 
62 |     string str2 = "Nineteen twenty five";
63 |     int length2 = str2.length();
64 |     solve(str2, length2);
65 |     return 0;
66 | }
67 | 


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/Striver TCS Sheet/05]. Problems_on_String/03_Find_the_ASCII_value_of_a_character.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find the ASCII value of a character
 3 | Problem Statement: Given a character, Find the ASCII value of the character.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: c = ‘A’
 9 | Output: 65
10 | Explanation: ASCII value of A is 65
11 | 
12 | Example 2:
13 | Input: c = ‘e’
14 | Output: 101
15 | Explanation: ASCII value of e is 101
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void get_ASCII_value(char c){
22 |     cout<<(int)c<<endl;
23 | }
24 | 
25 | int main()
26 | {
27 |     char c = 'A';
28 |     get_ASCII_value(c);
29 |     c = 'e';
30 |     get_ASCII_value(c);
31 | 
32 |     return 0;
33 | }
34 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/04_Remove_all_vowels_from_the_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove all vowels from the String
 3 | Problem Statement: Given a String, write a program to remove vowels from a given String.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: Str = “take u forward”
 9 | Output: tk  frwrd
10 | Explanation: All vowels are removed from the given String.
11 | 
12 | Example 2:
13 | Input: Str = “I am very happy today”
14 | Output:  m vry happy tdy
15 | Explanation: All vowels are removed from the given String.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void RemoveVowels(string s){
22 |     string res="";
23 |     for(int i=0; i<s.length(); i++){
24 |         if(s[i]=='A' || s[i]=='E' || s[i]=='I' || s[i]=='O' || s[i]=='U' || 
25 |            s[i]=='a' || s[i]=='e' || s[i]=='i' || s[i]=='o' || s[i]=='u'){
26 |                 continue;
27 |            }
28 |            else{
29 |             res+=s[i];
30 |            }
31 |     }
32 | 
33 |     for(int i=0; i<res.length(); i++){
34 |         cout<<res[i];
35 |     }
36 | }
37 | 
38 | int main()
39 | {
40 |   string str = "I am very happy today";
41 |   RemoveVowels(str);
42 |   return 0;
43 | }
44 | 


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/Striver TCS Sheet/05]. Problems_on_String/05_Remove_Spaces_from_a_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove Spaces from a String
 3 | Problem Statement: Given a string, write a program to remove all the whitespaces from the string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: str = “Take you forward” 
 9 | Output: Takeyouforward
10 | Explanation: After removing all the whitespaces Takeyouforward is the result
11 | 
12 | Example 2:
13 | Input: str = “How are you doing”
14 | Output: Howareyoudoing
15 | Explanation: After removing all the whitespaces Howareyoudoing is the result
16 | 
17 | */ 
18 | 
19 | #include<iostream>
20 | using namespace std;
21 | 
22 | void removeSpaces(string s){
23 |     for(int i=0; s[i]!='\0'; i++){
24 |         if(s[i]!=' '){
25 |             cout<<s[i];
26 |         }
27 |     }
28 | }
29 | 
30 | int main()
31 | {
32 |     string str = "How are you doing";
33 | 
34 |     removeSpaces(str);
35 |     return 0;
36 | }
37 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/06_Remove_characters_from_a_string_except_alphabets.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove characters from a string except alphabets
 3 | Problem Statement: Write a program to remove all characters from a string except alphabets in a given string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: string str = "take12% *&u ^$#forward"
 9 | Output: takeuforward
10 | Explanation:
11 | Characters 1,2,%,*,&,^,$,# along with whitespaces are 
12 | removed but the order of remaining alphabets is preserved.
13 | 
14 | Example 2:
15 | Input: String str = "1.Python & 2.Java"
16 | Output: PythonJava
17 | Explanation: 
18 | Characters 1.&2. along with whitespaces are removed 
19 | but the order of remaining alphabets is preserved.
20 | */ 
21 | 
22 | #include<bits/stdc++.h>
23 | using namespace std;
24 | 
25 | void removeCharacters(string s){
26 |     for(int i=0; i<s.length(); i++){
27 |         if((s[i] >= 'A' && s[i]<='Z') || (s[i] >= 'a' && s[i] <= 'z') ){
28 |             cout<<s[i];
29 |         }
30 |     }
31 | }
32 | 
33 | int main()
34 | {
35 |     string s = "Mr12% *& ^$#Vicky" ;
36 |     removeCharacters(s);
37 |     return 0;
38 | }
39 | 


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/Striver TCS Sheet/05]. Problems_on_String/07_Reverse_a_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Reverse a String
 3 | Problem Statement: Reverse a String. Write a program that reverses a given string (in-place).
 4 | 
 5 | Examples:
 6 | INPUT: HELLO
 7 | OUTPUT: OLLEH
 8 | 
 9 | INPUT: I AM IRON MAN
10 | OUTPUT: NAM NORI MA I
11 | */ 
12 | #include<bits/stdc++.h>
13 | using namespace std;
14 | 
15 | // Method 1: 
16 | // TC: O(n)
17 | // SC: O(1)
18 | void getReverse1(string s){
19 |     for(int i=s.length(); i>=0; i--){
20 |         cout<<s[i];
21 |     }
22 |     cout<<endl;
23 | }
24 | 
25 | // Method 2: 
26 | // TC: O(n)
27 | // SC: O(1)
28 | void getReverse2(string s){
29 |     reverse(s.begin(), s.end());
30 |     for(int i=0; i<s.length(); i++){
31 |         cout<<s[i];
32 |     }
33 |     cout<<endl;
34 | }
35 | 
36 | int main()
37 | {
38 |     string s = "I AM IRON MAN";
39 |     getReverse1(s);
40 |     getReverse2(s);
41 | 
42 |     return 0;
43 | }
44 | 


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/Striver TCS Sheet/05]. Problems_on_String/08_Remove_brackets_from_an_algebraic_expression.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove brackets from an algebraic expression
 3 | In this article, we will solve the most asked interview question: “Remove brackets from an algebraic expression”
 4 | 
 5 | Problem Statement: 
 6 | 
 7 | Remove brackets from an algebraic expression
 8 | 
 9 | Write a program to remove brackets from an algebraic expression
10 | 
11 | Given an algebraic expression, we need to simplify the expression and remove the brackets.
12 | 
13 | Examples:
14 | 
15 | Example 1:
16 | Input: “a+((b-c)+d)”
17 | Output: “a+b-c+d”
18 | Explanation: Removed all the brackets in the algebric expression.
19 | 
20 | Example 2:
21 | Input: “(((a-b))+c)”
22 | Output: “a-b+c”
23 | Explanation: Removed all the brackets in the algebric expression.
24 | */ 
25 | 
26 | #include<bits/stdc++.h>
27 | using namespace std;
28 | 
29 | void removeBrackets(string s){
30 |     for(int i=0; s[i]!='\0'; i++){
31 |         if(s[i]!='(' && s[i]!=')'){
32 |             cout<<s[i];
33 |         }
34 |     }
35 | }
36 | 
37 | int main()
38 | {
39 |     string str =  "(((a-b))+c)";
40 |     removeBrackets(str);
41 |     return 0;
42 | }
43 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/10_Capitalize_first_and_last_character_of_each_word_of_a_string.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Capitalize first and last character of each word of a string
 3 | Problem Statement: Given a string, write a program to Capitalize the first and last character of each word of that string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: String str = "take u forward is awesome"
 9 | Output: “TakE U ForwarD IS AwesomE”
10 | Explanation: We get the result after capitalizing the first and last character of each word of a string
11 | 
12 | Example 2:
13 | Input: String str = "Take u Forward is Awesome"
14 | Output: “TakE U ForwarD IS AwesomE”
15 | Explanation: Characters T, F, A are initially in uppercase , so they remain as they are in the result.
16 | */ 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | void capitalize(string s){
21 |     int n = s.length();
22 |     if(s[0] >= 'a' && s[0] <= 'z')
23 |          s[0]-=32;
24 | 
25 |     if(s[n-1] >= 'a' && s[n-1] <= 'z')
26 |         s[n-1]-=32;
27 |     
28 |     for(int i=1; i<n-1; i++){
29 | 
30 |         if((s[i-1]==' ' || s[i+1]==' ' ) && (s[i] >= 'a' && s[i] <= 'z')){
31 |             s[i]-=32;
32 |         }
33 |     }
34 | 
35 |     for(int i=0; i<n; i++){
36 |         cout<<s[i];
37 |     }
38 | }
39 | 
40 | int main()
41 | {
42 |     string s = "I am Iron Man";
43 |     capitalize(s);
44 |     return 0;
45 | }
46 | 


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/Striver TCS Sheet/05]. Problems_on_String/11_Calculate_Frequency_of_characters_in_a_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Calculate Frequency of characters in a String
 3 | Problem Statement: Given a string, calculate the frequency of characters in a string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: takeuforward
 9 | Output: a2 d1 e1 f1 k1 o1 r2 t1 u1 w1 
10 | Explanation: Count of every character of string is printed.
11 | 
12 | Example 2:
13 | Input: articles
14 | Output: a1 c1 e1 i1 l1 r1 s1 t1 
15 | Explanation: Count of every character of string is printed.
16 | */ 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | void Printfrequency(string s){
21 |     map<char, int>mp;
22 | 
23 |     for(int i=0; i<s.length(); i++){
24 |         mp[s[i]]++;
25 |     }
26 |     
27 |     for(auto x: mp){
28 |         cout<<x.first<<x.second<<" ";
29 |     }
30 | }
31 | 
32 | int main()
33 | {
34 |     string str = "Extraordinary";
35 |     Printfrequency(str);
36 |     return 0;
37 | }
38 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/12_Find_Non_repeating_characters_of_a_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Find Non-repeating characters of a String
 3 | Problem:  Given a string, print non-repeating characters of the string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: string = “google”
 9 | Output: l,e
10 | 
11 | Explanation: Non repeating characters are l,e.
12 | 
13 | Example 2:
14 | Input: string = “yahoo”
15 | Output: y,a,h
16 | Explanation: Non repeating characters are y,a,h
17 | */ 
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | void getNonRepeating(string s){
23 |     map<char, int>mp;
24 | 
25 |     for(int i=0; i<s.length(); i++){
26 |         mp[s[i]]++;
27 |     }
28 |     
29 |     for(auto x: mp){
30 |         if(x.second==1){
31 |             cout<<x.first<<" ";
32 |         }
33 |     }
34 | }
35 | 
36 | int main()
37 | {
38 |  
39 |     string str = "google";
40 |     getNonRepeating(str);
41 | 
42 |     return 0;
43 | }
44 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/13_Check_if_two_Strings_are_anagrams_of_each_other.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Check if two Strings are anagrams of each other
 3 | Problem Statement: Given two strings, check if two strings are anagrams of each other or not.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: CAT, ACT
 9 | Output: true
10 | Explanation: Since the count of every letter of both strings are equal.
11 | 
12 | Example 2:
13 | Input: RULES, LESRT 
14 | Output: false
15 | Explanation: Since the count of U and T  is not equal in both strings.
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | bool isAnagram(string s1, string s2){
22 |     sort(s1.begin(), s1.end());
23 |     sort(s2.begin(), s2.end());
24 | 
25 |     if(s1.length()!=s2.length()){
26 |         return false;
27 |     }
28 |     for(int i=0; i<s1.length(); i++){
29 |         if(s1[i]!=s2[i]){
30 |             return false;
31 |         }
32 |     }
33 |     return true;
34 | }
35 | 
36 | int main()
37 | {
38 |     string str1 = "ACT";
39 |     string str2 = "CAT";
40 |     cout<<boolalpha<<isAnagram(str1, str2);
41 |     return 0;
42 | }
43 | 


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/16_Maximum_occurring_character_in_a_string.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Maximum occurring character in a string
 3 | Maximum occurring character in a string
 4 | 
 5 | Problem Statement: Given a string, return the character that occurs the maximum number of times in the string. If the maximum occurrence of two or more characters is the same, return any one of them. 
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input: str = “takeuforward”
11 | Output: a
12 | Explanation: The character 'a' and 'r’ have the same  maximum occurrence i.e 2. Hence we can print any one of them
13 | 
14 | Example 2:
15 | Input: str = “apple”
16 | Output: p
17 | Explanation: The character 'p' have the maximum occurrence i.e 2.
18 | */ 
19 | 
20 | #include<bits/stdc++.h>
21 | using namespace std;
22 | 
23 | void getMaximumOccuring(string s){
24 |     map<char, int>mp;
25 |     int n = s.length();
26 |     for(int i=0; i<n; i++){
27 |         mp[s[i]]++;
28 |     }
29 | 
30 |     int max_occuring = 0;
31 |     for(auto x: mp){
32 |         max_occuring = max(max_occuring, x.second);
33 |     }
34 | 
35 |     for(auto x: mp){
36 |         if(x.second==max_occuring){
37 |             cout<<x.first<<endl;
38 |             break;
39 |         }
40 |     }
41 | }
42 | 
43 | int main()
44 | {
45 |     string str = "takeuforward";
46 |     getMaximumOccuring(str);
47 |     getMaximumOccuring("apple");
48 |     return 0;
49 | }
50 | 


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/Striver TCS Sheet/05]. Problems_on_String/17_Remove_All_Duplicates_from_a_String.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Remove All Duplicates from a String
 3 | Problem Statement: Given a String remove all the duplicate characters from the given String.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: s = "bcabc"
 9 | Output: “bca"
10 | 
11 | Explanation: Duplicate Characters are removed
12 | Example 2:
13 | Input: s = "cbacdcbc"
14 | Output: "cbad" 
15 | Explanation: Duplicate Characters are removed
16 | */ 
17 | 
18 | #include<bits/stdc++.h>
19 | using namespace std;
20 | 
21 | void removeDupicates(string s){
22 |     unordered_map<char, int>ump;
23 |     for(int i=0; i<s.length(); i++){
24 |         ump[s[i]]++;
25 |     }
26 | 
27 |     for(auto x: ump){
28 |         cout<<x.first;
29 |     }
30 | }
31 | 
32 | int main()
33 | {
34 |     string s = "cbacdcbc";
35 |     removeDupicates(s);
36 |     return 0;
37 | }


--------------------------------------------------------------------------------
/Striver TCS Sheet/05]. Problems_on_String/18_Print_all_the_duplicates_in_the_string.cpp:
--------------------------------------------------------------------------------
 1 | /*
 2 | Print all the duplicates in the string
 3 | Print all the duplicates in the string
 4 | 
 5 | Problem Statement: Given a string of characters from a to z. Print the duplicate characters(which are occurring more than once) in the given string with their occurrences count.
 6 | 
 7 | Examples:
 8 | 
 9 | Example 1:
10 | Input:
11 |  str= "sinstriiintng"
12 | Output:
13 | i - 4
14 | n - 3
15 | s - 2
16 | t - 2
17 | Explanation:
18 | In the above example, 's' occurs twice, 'i' occurs four times, 't' occurs twice and 'n' occurs thrice. 'r' and 'g' occur only one time and hence are not considered.
19 | 
20 | Example 2:
21 | Input:
22 |  str= "abcdefg"
23 | Output:
24 | < -- No Output -- >
25 | Explanation:
26 | 
27 | In the above example, every character occurs only once(no duplicates), therefore nothing to print.
28 | 
29 | */ 
30 | 
31 | #include<bits/stdc++.h>
32 | using namespace std;
33 | 
34 | // TC: O(n)
35 | // SC: O(n)
36 | void getDuplicates(string s){
37 |     int n = s.length();
38 |     map<char, int>mp;
39 | 
40 |     for(int i=0; i<n; i++){
41 |         mp[s[i]]++;
42 |     }
43 | 
44 |     for(auto x: mp){
45 |         if(x.second>1){
46 |             cout<<x.first<<" - "<<x.second<<endl;
47 |         }
48 |     }
49 | }
50 | 
51 | int main()
52 | {
53 |     string str = "sinstriiintng";
54 |     getDuplicates(str);
55 | 
56 |     return 0;
57 | }
58 | 


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/Striver TCS Sheet/05]. Problems_on_String/19_Remove_Characters_from_first_String_present_in_the_Second_String.cpp:
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 1 | /*
 2 | Remove Characters from first String present in the Second String
 3 | Problem Statement: Given two strings, write a program to remove characters from the first string which are present in the second string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: String str1 = “abcdef”
 9 |        String str2 = “cefz”
10 | Output: abd
11 | Explanation: The common characters in both strings are c, e, f.
12 | So after removing these characters from string 1 we get string resulting string as abd.
13 | 
14 | 
15 | Example 2:
16 | Input: String str1 = “xyzpw”
17 |        String str2 = “lmno”
18 | Output: xyzpw
19 | Explanation: As there is no common character in both the strings, string 1 remains unchanged.
20 | */ 
21 | 
22 | #include<bits/stdc++.h>
23 | using namespace std;
24 | 
25 | // TC: O(n*n)
26 | // SC: O(1)
27 | void getCharacters(string s1, string s2){
28 |     for(int i=0; i<s1.length(); i++){
29 |         bool flag = false;
30 |         for(int j=0; j<s2.length(); j++){
31 |             if(s1[i]==s2[j]){
32 |                 flag = true;
33 |             }
34 |         }
35 |         if(flag==false){
36 |             cout<<s1[i];
37 |         }
38 | 
39 |     }
40 | }
41 | 
42 | int main()
43 | {
44 |     string s1 = "abcdef";
45 |     string s2 = "cefz";
46 | 
47 |     getCharacters(s1, s2);
48 |     return 0;
49 | }
50 | 


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/Striver TCS Sheet/05]. Problems_on_String/20_Change_every_letter_with_next_lexicographic_alphabet.cpp:
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 1 | /*
 2 | Change every letter with next lexicographic alphabet
 3 | Problem Statement: Given a string, write a program to change every letter in the given string with the letter following it in the alphabet (ie. a becomes b, p becomes q, z becomes a)
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: string str = “abcdxyz”
 9 | Output: bcdeyza
10 | Explanation:
11 | 
12 | Example 2:
13 | Input: string str = “Java”
14 | Output: Kbwb
15 | Explanation:
16 | 
17 | */ 
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | void changeLetter(string s){
23 |     int n = s.length();
24 |     for(int i=0; i<n; i++){
25 |         if(s[i]=='z'){
26 |             s[i]='a';
27 |         }
28 |         else 
29 |             s[i]+=1;
30 |     }
31 | 
32 |     for(int i=0; i<n; i++)
33 |         cout<<s[i];
34 |     cout<<endl;
35 | }
36 | 
37 | int main()
38 | {
39 |     string s = "abcdxyz";
40 |     changeLetter(s);
41 |     changeLetter("java");
42 |     return 0;
43 | }
44 | 


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/Striver TCS Sheet/05]. Problems_on_String/22_Write_a_program_to_sort_characters_in_a_string.cpp:
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 1 | /*
 2 | Write a program to sort characters in a string
 3 | Problem Statement:  Write a program to sort characters (numbers and punctuation symbols are not included) in a given string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: String str = “zxcbg”
 9 | Output: bcgxz
10 | Explanation: After sorting we get string as bcgxz
11 | 
12 | Example 2:
13 | Input: String str = “edcba”
14 | Output: abcde
15 | Explanation: After sorting we get string as abcde
16 | */ 
17 | #include<bits/stdc++.h>
18 | using namespace std;
19 | 
20 | // Method 1:
21 | void getSorted1(string s){
22 |     sort(s.begin(), s.end());
23 |     for(auto x: s)
24 |         cout<<x;
25 |     cout<<endl;
26 | }
27 | 
28 | // Method 2:
29 | void getSorted2(string s){
30 |     set<char>st(s.begin(), s.end());
31 |     for(auto x: st){
32 |         cout<<x;
33 |     }
34 |     cout<<endl;
35 | }
36 | 
37 | int main()
38 | {
39 |     string s = "zxcbg";
40 |     getSorted1(s);
41 |     getSorted2(s);
42 |     getSorted2("edcba");
43 |     return 0;
44 | }
45 | 


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/Striver TCS Sheet/05]. Problems_on_String/23_Count_the_number_of_words_in_a_given_string.cpp:
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 1 | /*
 2 | Count the number of words in a given string
 3 | Problem Statement: Write a program to count the number of words in a given string.
 4 | 
 5 | Examples:
 6 | INPUT: "HELLOW"
 7 | OUTPUT: 1
 8 | 
 9 | INPUT: "I am iron man"
10 | OUTPUT: 4
11 | */ 
12 | 
13 | #include<bits/stdc++.h>
14 | using namespace std;
15 | 
16 | void countWords(string s){
17 |     int count = 0;
18 |     for(int i=0; i<s.length(); i++){
19 |         if(s[i]==' '){
20 |             count++;
21 |         }
22 |     }
23 |     cout<<"Number of words: "<<count+1<<endl;
24 | }
25 | 
26 | 
27 | int main()
28 | {
29 |     string str = "I am iron man";
30 |     countWords(str);
31 |     return 0;
32 | }
33 | 


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/Striver TCS Sheet/05]. Problems_on_String/25_Change_case_of_each_character_in_a_string.cpp:
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 1 | /*
 2 | Change case of each character in a string
 3 | Problem Statement: Write a  program to change the case (lower to upper and upper to lower cases) of each character of a given string.
 4 | 
 5 | Examples:
 6 | 
 7 | Example 1:
 8 | Input: String str = “javA”
 9 | Output: JAVa
10 | Explanation:
11 |  Changed the lower case characters to uppercase and vice versa.
12 | 
13 | Example 2:
14 | Input: String str = “take u forward IS Awesome”
15 | Output: TAKE U FORWARD is aWESOME
16 | Explanation: Changed the lower case characters to uppercase and vice versa.
17 | */ 
18 | 
19 | #include<bits/stdc++.h>
20 | using namespace std;
21 | 
22 | void changeTheCase(string s){
23 |     for(int i=0; i<s.length(); i++){
24 |         if(s[i] > 'A' && s[i] < 'Z'){
25 |             s[i]+=32;
26 |         }
27 |         else if(s[i] > 'a' && s[i] < 'z'){
28 |             s[i]-=32;
29 |         }
30 |     }
31 | 
32 |     for(int i=0; i<s.length(); i++){
33 |         cout<<s[i];
34 |     }
35 | }
36 | 
37 | int main()
38 | {
39 |     string str = "Iron Man";
40 |     changeTheCase(str);
41 |     return 0;
42 | }
43 | 


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/Striver TCS Sheet/05]. Problems_on_String/26_Concatenate_one_string_to_another.cpp:
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 1 | /*
 2 | Concatenate one string to another
 3 | Problem Statement: Concatenate one string to another. Write a program to concatenate one string’s contents to another. Concatenation means to join two (or more) strings and form a combined string having the characters of both ( or all) strings in the same order as they were before in separate strings.
 4 | 
 5 | Examples:
 6 | INPUT: s1 = "Hello" s2="World" 
 7 | OUTPUT: "HelloWorld"
 8 | */ 
 9 | 
10 | #include<bits/stdc++.h>
11 | using namespace std;
12 | 
13 | string concatinate(string s1, string s2){
14 |     return s1+s2;
15 | }
16 | 
17 | int main()
18 | {
19 |     string s1="Hello";
20 |     string s2="World";
21 |     cout<<concatinate(s1, s2);
22 |     return 0;
23 | }
24 | 


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/Striver TCS Sheet/05]. Problems_on_String/README.md:
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1 | # Problems on String


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/Striver TCS Sheet/README.md:
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 1 | # [**TCS NQT Coding Sheet**](https://takeuforward.org/interviews/tcs-nqt-coding-sheet-tcs-coding-questions/#point_1) – TCS Coding Questions
 2 | 
 3 | <!-- ## `INDEX`
 4 | 
 5 | - 01]. [Problems on Array](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/01%5D.%20Arrays)
 6 | - 02]. [Problems on Numbers](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/02%5D.%20Problems_on_Numbers)
 7 | - 03]. [Problems on Number System](#)
 8 | - 04]. [Problems on Sorting](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/04%5D.%20Problems_on_Sorting)
 9 | - 05]. [Problems on String](https://github.com/mr-vicky/TCS-NQT-Coding-Sheet/tree/main/05%5D.%20Problems_on_String) -->
10 | 


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