├── README.md
├── Linked List
    ├── Detect-Loop-In-Linked-List.py
    ├── CircularLinkedList.cpp
    ├── DoublyLinkedList.cpp
    └── SinglyLinkedList.cpp
├── Graph
    ├── BFSOfTree.cpp
    ├── Graph - BFS DFS.cpp
    ├── BfsLevelOrderTraversalOnBinaryTree.cpp
    ├── Graph Krushkals.cpp
    ├── Graph representation using set and hash
    └── Graph Prims.cpp
├── Trie
    └── trie.cpp
├── C++ Header files and Operators.cpp
├── Heaps
    ├── Heap - Heapify.cpp
    └── Heap- MIN and MAX.cpp
├── Stack
    ├── Stack.cpp
    └── stack-using-queue.cpp
├── Hashing
├── Segment Tree
    ├── segmenttree(max).cpp
    ├── segmenttree.cpp
    └── Segment_tree.cpp
└── Trees
    ├── BinarySearchTree.cpp
    └── AVL-Tree.cpp


/README.md:
--------------------------------------------------------------------------------
1 | # data-structures-algorithms
2 | Codes for important Data Structures and Algorithms (Mostly C++)
3 | 
4 | 


--------------------------------------------------------------------------------
/Linked List/Detect-Loop-In-Linked-List.py:
--------------------------------------------------------------------------------
 1 | #The idea is to keep two pointers one will be incremented by one and other by two,
 2 | #If they meet at same node at any point then there is loop in linked list
 3 | def detect_loop(head): #returns True if loop is present
 4 | 	pointer1 = head
 5 | 	pointer2 = head
 6 | 	while pointer1 and pointer2 and pointer2.next:
 7 | 		pointer1 = pointer1.next
 8 | 		pointer2 = pointer2.next.next
 9 | 		if pointer1 == pointer2:
10 | 			return True
11 | 	return False
12 | 


--------------------------------------------------------------------------------
/Graph/BFSOfTree.cpp:
--------------------------------------------------------------------------------
 1 | #include<iostream>
 2 | #include<queue>
 3 | using namespace std;
 4 | class node{
 5 | 	public:
 6 | 		int val;
 7 | 		node * left;
 8 | 		node * right;
 9 | };
10 | node * addNode(int v){
11 | 	node * n=new node();
12 | 	n->val=v;
13 | 	n->left=NULL;
14 | 	n->right=NULL;
15 | }
16 | 
17 | int bfs(node * tree){
18 | 	int s;
19 | 	if(tree==NULL) return 0;
20 | 	queue<node *> q;
21 | 	q.push(tree);
22 | 	while(q.empty()==false){
23 | 		s=q.size();
24 | 		for(int i=0;i<s;i++){
25 | 			node *t=q.front();
26 | 			q.pop();
27 | 			cout<<t->val<<" ";
28 | 			if(t->left) q.push(t->left);
29 | 			if(t->right) q.push(t->right);
30 | 		}
31 | 	}
32 | 	return 0;
33 | }
34 | int main(){
35 | 	node *tree;
36 | 	tree=addNode(1);
37 | 	tree->left=addNode(2);
38 | 	tree->right=addNode(3);
39 | 	tree->left->left=addNode(5);
40 | 	tree->left->right=addNode(4);
41 | 	tree->right->left=addNode(6);
42 | 	bfs(tree);
43 | }
44 | 


--------------------------------------------------------------------------------
/Graph/Graph - BFS DFS.cpp:
--------------------------------------------------------------------------------
 1 | #include<bits/stdc++.h>
 2 | using namespace std;
 3 | #define MAX 100
 4 | 
 5 | int A[MAX][MAX], visitedB[MAX] = {0},visitedD[MAX] = {0};
 6 | 
 7 | void BFS(int root,int limit)
 8 | {
 9 |     int u;
10 |     cout<<root<<" ";
11 |     visitedB[root] = 1;
12 |     queue <int> q1;
13 |     q1.push(root);
14 |     while(!q1.empty())
15 |     {
16 |         u = q1.front();
17 |         q1.pop();
18 |         for(int i=1;i<limit;i++)
19 |         {
20 |             if((A[u][i] == 1) and (visitedB[i] == 0))
21 |             {
22 |                 cout<<i<<" ";
23 |                 visitedB[i] = 1;
24 |                 q1.push(i);
25 |             }
26 |         }
27 |     }
28 | }
29 | 
30 | void DFS(int root,int limit)
31 | {
32 |     if(visitedD[root]==0)
33 |     {
34 |         cout<<root<<" ";
35 |         visitedD[root] = 1;
36 |         for(int i=0;i<limit;i++)
37 |         {
38 |             if((A[root][i]==1) and (visitedD[i]==0))
39 |                 DFS(i,limit);
40 |         }
41 |     }
42 | }
43 | 
44 | int main()
45 | {
46 | 
47 | 
48 |     for(int i=0;i<MAX;i++)
49 |     {
50 |         A[0][i]= 0;
51 |         A[i][0]= 0;
52 |     }
53 |     int vertex_count;
54 |     cout<<"Enter the number of vertex:- ";
55 |     cin>>vertex_count;
56 | 
57 |     for(int i=1;i<vertex_count+1;i++)
58 |         for(int j=1;j<vertex_count+1;j++)
59 |         {
60 |             cout<<"If there is edge between "<<i<<" and "<<j<<" Press 1 else 0: ";
61 |             cin>>A[i][j];
62 |         }
63 | 
64 |     cout<<"\nBFS: ";
65 |     BFS(1,vertex_count+1);
66 | 
67 |     cout<<"\nDFS: ";
68 |     DFS(1,vertex_count+1);
69 | }
70 | 


--------------------------------------------------------------------------------
/Graph/BfsLevelOrderTraversalOnBinaryTree.cpp:
--------------------------------------------------------------------------------
 1 | #include<iostream>
 2 | #include<vector>
 3 | #include<queue>
 4 | #include<stdlib.h>
 5 | using namespace std;
 6 | typedef struct node{
 7 | 	int data;
 8 | 	struct node * left;
 9 | 	struct node * right;
10 | }node;
11 | 
12 | node * addNode(int val){
13 | 	node *t=(node *) calloc(sizeof(node),1);
14 | 	t->data=val;
15 | 	t->left=NULL;
16 | 	t->right=NULL;
17 | 	return t;
18 | }
19 | void createTree(node **G,int n){
20 | 	while(n){
21 | 		int m,p,val;
22 | 		cout<<"Enter node value :";
23 | 		cin>>val;
24 | 		G[val]=addNode(val);
25 | 		n--;
26 | 		cout<<"Enter left node and right node values( -1 for null ) :";
27 | 		cin>>m>>p;
28 | 		if(m==-1) n--;
29 | 		if(p==-1) n--;
30 | 		G[val]->left=addNode(m);
31 | 		G[val]->right=addNode(p);
32 | 		
33 | 	}
34 | 	cout<<"TREE\n";
35 | 	for(int i=0;i<n;i++){
36 | 		cout<<G[i]->data<<" : ";
37 | 		cout<<G[i]->left->data <<" "<<G[i]->right->data<<endl;
38 | 	}
39 | }
40 | 
41 | // below part is correct logic
42 | vector<vector<int> > bfs(node **G,int n){
43 | 	vector<vector<int> > res;
44 | 	queue<node *> q;
45 | 	q.push(G[0]);
46 | 	cout<<"Bfs\n";
47 | 	while(!q.empty()){
48 | 		int s=q.size();
49 | 		vector<int> v;
50 | 		for(int i=0;i<s;i++){
51 | 		node *t=q.front();
52 | 		q.pop();
53 | 		cout<<t->data<<endl;
54 | 		v.push_back(t->data);
55 | 		if(t->left)		q.push(G[i]->left);
56 | 		if(t->right)	q.push(G[i]->right);
57 | 		}
58 | 		res.push_back(v);
59 | 	}
60 | 	return res;
61 | 	
62 | }
63 | 
64 | int main(){
65 | 	vector<vector<int> > vec;
66 | 	int i,j,n;
67 | 	cout<<"Enter number of nodes present :";
68 | 	cin>>n;
69 | 	node **G=(node **)calloc(sizeof(node *),n);
70 | 	createTree(G,n);
71 | 	vec=bfs(G,n);
72 | 	return 0;
73 | }
74 | 


--------------------------------------------------------------------------------
/Trie/trie.cpp:
--------------------------------------------------------------------------------
 1 | #include<iostream>
 2 | using namespace std;
 3 | 
 4 | struct node{
 5 | 	node *next[150] = {NULL};
 6 | 	int eow = 0;
 7 | 	string meaning = "kothariji";
 8 | }*head = NULL,t1;
 9 | 
10 | void insert(string s, string mean)
11 | {
12 | 	if(head == NULL)
13 | 		head  = new node;
14 | 	
15 | 	node *temp = head;
16 | 	int i = 0;
17 | 	while(i< s.length() and temp -> next[s[i]-'a'] != NULL)
18 | 	{
19 | 		temp = temp -> next[s[i]-'a'];
20 | 		i++;
21 | 	}
22 | 	while(i<s.length())
23 | 	{
24 | 		node *t1 = new node;
25 | 		temp -> next[s[i]-'a'] = t1;
26 | 		temp = t1;
27 | 		i++;
28 | 	}
29 | 		temp -> meaning = mean;
30 | }
31 | 
32 | void search(string s)
33 | {
34 | 	int i = 0,flag = 0;
35 | 	node *temp = head;
36 | 	while(i < s.length())
37 | 	{
38 | 		if(temp -> next[s[i]-'a'] == NULL)
39 | 		{
40 | 			flag =1;
41 | 			break;
42 | 		}
43 | 		temp = temp -> next[s[i]-'a'];
44 | 		i++;
45 | 	}
46 | 	if(flag == 0 and temp -> meaning != "kothariji")
47 | 		cout<<"Meaning: "<<" "<<temp -> meaning<<"\n\n"<<endl;
48 | 	else
49 | 		cout<<"No such word Found!"<<endl;
50 | }
51 | 
52 | int main()
53 | {
54 |     string w, m;
55 | 	while(1)
56 | 	{
57 | 		int ch;
58 | 		cout<<"Press 1 to insert a word and its meaning"<<endl;
59 | 		cout<<"Press 2 to search meaning of a word"<<endl;
60 | 		cout<<"Press 3 to exit"<<endl;
61 | 		cin>>ch;
62 | 		switch(ch)
63 | 		{
64 | 			case 1: cout<<"Enter Word: ";
65 | 					cin>>w;
66 | 					cout<<"Enter meaning: ";
67 | 					cin>>m;
68 | 					insert(w,m);
69 | 					cout<<"\n\nWord inserted successfully\n\n"<<endl;
70 | 					break;
71 | 
72 | 			case 2: cout<<"Enter Word to search: ";
73 | 					cin>>w;
74 | 					search(w);
75 | 					break;
76 | 
77 | 			case 3: cout<<"Thanks for using our service!"<<endl;
78 | 					return 0;
79 | 					
80 | 			default: 	cout<<"Enter a valid input"<<endl;								
81 | 						break;
82 | 		}
83 | 	}
84 | }
85 | 


--------------------------------------------------------------------------------
/C++ Header files and Operators.cpp:
--------------------------------------------------------------------------------
 1 | // There are two types of header files:
 2 | // 1. System header files: It comes with the compiler
 3 | #include<iostream>
 4 | // 2. User defined header files: It is written by the programmer
 5 | // #include "this.h" //--> This will produce an error if this.h is no present in the current directory
 6 | 
 7 | using namespace std;
 8 | 
 9 | int main(){
10 |     int a=4, b=5;
11 |     cout<<"Operators in C++:"<<endl;
12 |     cout<<"Following are the types of operators in C++"<<endl;
13 |     // Arithmetic operators
14 |     cout<<"The value of a + b is "<<a+b<<endl;
15 |     cout<<"The value of a - b is "<<a-b<<endl;
16 |     cout<<"The value of a * b is "<<a*b<<endl;
17 |     cout<<"The value of a / b is "<<a/b<<endl;
18 |     cout<<"The value of a % b is "<<a%b<<endl;
19 |     cout<<"The value of a++ is "<<a++<<endl;
20 |     cout<<"The value of a-- is "<<a--<<endl;
21 |     cout<<"The value of ++a is "<<++a<<endl;
22 |     cout<<"The value of --a is "<<--a<<endl;
23 |     cout<<endl;
24 | 
25 |     // Assignment Operators --> used to assign values to variables
26 |     // int a =3, b=9;
27 |     // char d='d';
28 | 
29 |     // Comparison operators
30 |     cout<<"Following are the comparison operators in C++"<<endl;
31 |     cout<<"The value of a == b is "<<(a==b)<<endl;
32 |     cout<<"The value of a != b is "<<(a!=b)<<endl;
33 |     cout<<"The value of a >= b is "<<(a>=b)<<endl;
34 |     cout<<"The value of a <= b is "<<(a<=b)<<endl;
35 |     cout<<"The value of a > b is "<<(a>b)<<endl;
36 |     cout<<"The value of a < b is "<<(a<b)<<endl;
37 | 
38 |     // Logical operators
39 |     cout<<"Following are the logical operators in C++"<<endl;
40 |     cout<<"The value of this logical and operator ((a==b) && (a<b)) is:"<<((a==b) && (a<b))<<endl;
41 |     cout<<"The value of this logical or operator ((a==b) || (a<b)) is:"<<((a==b) || (a<b))<<endl;
42 |     cout<<"The value of this logical not operator (!(a==b)) is:"<<(!(a==b))<<endl;
43 | 
44 | 
45 |     return 0;
46 | }
47 | 


--------------------------------------------------------------------------------
/Heaps/Heap - Heapify.cpp:
--------------------------------------------------------------------------------
 1 | #include <bits/stdc++.h>
 2 | using namespace std;
 3 | #define MAX 100
 4 | 
 5 | int heap[MAX];
 6 | 
 7 |     void heapify(int len, int start_index)
 8 |     {
 9 |         int i = start_index;
10 |         int lc = 2*start_index;
11 |         int rc = 2*start_index+1;
12 |         int temp;
13 | 
14 | 
15 |         /******checking for left child******/
16 | 
17 | 
18 |         if (lc < len and heap[i] < heap[lc])
19 |         {
20 |             i = lc;
21 |             swap(heap[i],heap[start_index]);
22 |         }
23 | 
24 |         /******checking for right child******/
25 | 
26 |         if (rc < len and heap[i] < heap[rc])
27 |         {
28 |             i = rc;
29 |             swap(heap[i],heap[start_index]);
30 |         }
31 | 
32 | 
33 |         /******recursively calling heapify for the parent subtree******/
34 | 
35 |         if(i != start_index)
36 |             heapify(len,i);
37 |     }
38 | 
39 |     /******Display of MAX heap******/
40 | 
41 |     void display(int len)
42 |     {
43 |         cout<<"\n========================================\n";
44 |         cout<<"HEAP: ";
45 |         for(int i=1; i <= len; i++)
46 |             cout<<heap[i]<<" ";
47 |         cout<<"\n========================================";
48 |     }
49 | 
50 | 
51 | int main()
52 | {
53 |     int len,data,ind=0;
54 |     cout<<"Enter the number of elements to be entered in Heap: ";
55 |     cin>>len;
56 |     heap[ind] = 0;
57 | 
58 |     /******Inserting values******/
59 | 
60 |     for(int ind=1;ind<=len;ind++)
61 |     {
62 |         cout<<"Enter "<<ind<<" element: ";
63 |         cin>>heap[ind];
64 |     }
65 | 
66 |     /******getting of index of first non leaf root******/
67 |     int start_index = (len/2);
68 | 
69 |     /******heapify all elements******/
70 |     for(int i= start_index; i>=1; i--)
71 |     {
72 |         heapify(len,i);
73 |     }
74 |     /******display heap******/
75 |     display(len);
76 | }
77 | 


--------------------------------------------------------------------------------
/Stack/Stack.cpp:
--------------------------------------------------------------------------------
  1 | #include<iostream>
  2 | #include<string.h>
  3 |  
  4 | using namespace std;
  5 | 
  6 | typedef struct node
  7 | {
  8 |     char data;
  9 |     struct node *next;
 10 | }node;
 11 |  
 12 | class stack
 13 | {
 14 |     node *top;
 15 |     public:
 16 |     stack()
 17 |     {
 18 |         top=NULL;
 19 |     }
 20 |  
 21 | int isEmpty()
 22 | {
 23 |     if(top==NULL)
 24 |     {
 25 |         return 1;
 26 |     }
 27 | return 0;
 28 | }
 29 |  
 30 |  
 31 | int push(char data)
 32 | {
 33 |     node *p;
 34 |     p=new node();
 35 |     p->data=data;
 36 |     p->next=top;
 37 |     top=p;
 38 |     return p->data; 
 39 | }
 40 |  
 41 |  
 42 | int pop()
 43 | { 
 44 |     char x;
 45 |     node *p;
 46 |     p=top;
 47 |     x=top->data;
 48 |     top=top->next;
 49 |     delete(p);
 50 |     return x; 
 51 | }
 52 |  
 53 |  
 54 | void display()
 55 | {
 56 |     node *p;
 57 |     for(p=top;p!=NULL;p=p->next)
 58 |     {
 59 |         cout<<p->data<<"-";
 60 |     }
 61 | }
 62 | 
 63 | int topData()
 64 | {
 65 | 	return top->data;
 66 | }
 67 |  
 68 | }; 
 69 |  
 70 | int main()
 71 | {
 72 |     stack k;
 73 |     char a,b,data;
 74 |     int ch;
 75 |     
 76 |     while(1){
 77 |         
 78 |         cout<<"\n1-Push\n2-Pop\n3-Display\n4-Exit\nEnter your choice!!!\n";
 79 |         cin>>ch;
 80 |          
 81 |         switch(ch){
 82 |             case 1: cout<<"\nEnter the data-\t";
 83 |                     cin>>data;
 84 |                     b=k.push(data);
 85 |                     cout<<"Successfully pushed->"<<b;
 86 |                     break;
 87 |             
 88 |             case 2: a=k.pop();
 89 |                     cout<<"Successfully poped->"<<a;
 90 |                     break;
 91 |             
 92 |             case 3: k.display();
 93 |                     break;
 94 |             
 95 |             case 4: return 0;
 96 |                     break;
 97 |             default:cout<<"\nWrong Choice\n";
 98 |         }
 99 |     }
100 |  
101 | }
102 | 


--------------------------------------------------------------------------------
/Graph/Graph Krushkals.cpp:
--------------------------------------------------------------------------------
 1 | #include<bits/stdc++.h>
 2 | using namespace std;
 3 | #define MAX 100
 4 | #define I INT_MAX
 5 | 
 6 | int edge[3][MAX];
 7 | int s[MAX];
 8 | int included[MAX];
 9 | int t[2][MAX];
10 | 
11 | void union1(int u, int v)
12 | {
13 |     if(s[u] < s[v])
14 |     {
15 |         s[u] = s[u] + s[v];
16 |         s[v] = u;
17 |     }
18 |     else
19 |     {
20 |         s[v] = s[u] + s[v];
21 |         s[u] = v;
22 |     }
23 | }
24 | 
25 | int find(int u)
26 | {
27 |     int x = u;
28 |     while(s[x] > 0)
29 |     {
30 |         x = s[x];
31 |     }
32 |     return x;
33 | }
34 | 
35 | 
36 | int main()
37 | {
38 |     memset(s,-1,sizeof(s));
39 |     memset(included,0,sizeof(included));
40 |     int vertex_count, edge_count, total_weight = 0;
41 |     cout<<"Enter the number of vertex: ";
42 |     cin>>vertex_count;
43 |     cout<<"Enter the number of edges: ";
44 |     cin>>edge_count;
45 |     for(int i= 0;i < edge_count;i++)
46 |     {
47 |         cout<<"Enter vertex 1: ";
48 |         cin>>edge[0][i];
49 |         cout<<"Enter vertex 2: ";
50 |         cin>>edge[1][i];
51 |         cout<<"Enter edge weight: ";
52 |         cin>>edge[2][i];
53 |     }
54 | 
55 |     int i=0,j,k,min,u,v;
56 | 
57 |     while(i < vertex_count-1)
58 |     {
59 |         min = I;
60 |         for(j = 0; j < edge_count ; j++)
61 |         {
62 |             if((included[j]==0) and (edge[2][j] < min))
63 |             {
64 |                 min = edge[2][j];
65 |                 k = j;
66 |                 u = edge[0][j];
67 |                 v = edge[1][j];
68 |             }
69 |         }
70 | 
71 |         if(find(u) != find(v))
72 |         {
73 |             t[0][i] = u;
74 |             t[1][i] = v;
75 |             total_weight += edge[2][k];
76 |             union1(find(u), find(v));
77 |             i++;
78 |         }
79 |         included[k] = 1;
80 |     }
81 | 
82 | 
83 |     for(int i = 0; i < vertex_count-1; i++)
84 |         cout<<t[0][i]<<"  "<<t[1][i]<<endl;
85 | 
86 |     cout<<"\nTotal weight: "<<total_weight<<endl;
87 | 
88 |     return 0;
89 | }
90 | 


--------------------------------------------------------------------------------
/Graph/Graph representation using set and hash:
--------------------------------------------------------------------------------
 1 | // A C++ program to demonstrate adjacency list 
 2 | // representation of graphs using sets 
 3 | #include <bits/stdc++.h> 
 4 | using namespace std; 
 5 | 
 6 | struct Graph { 
 7 | 	int V; 
 8 | 	set<int, greater<int> >* adjList; 
 9 | }; 
10 | 
11 | // A utility function that creates a graph of V vertices 
12 | Graph* createGraph(int V) 
13 | { 
14 | 	Graph* graph = new Graph; 
15 | 	graph->V = V; 
16 | 
17 | 	// Create an array of sets representing 
18 | 	// adjacency lists. Size of the array will be V 
19 | 	graph->adjList = new set<int, greater<int> >[V]; 
20 | 
21 | 	return graph; 
22 | } 
23 | 
24 | // Adds an edge to an undirected graph 
25 | void addEdge(Graph* graph, int src, int dest) 
26 | { 
27 | 	// Add an edge from src to dest. A new 
28 | 	// element is inserted to the adjacent 
29 | 	// list of src. 
30 | 	graph->adjList[src].insert(dest); 
31 | 
32 | 	// Since graph is undirected, add an edge 
33 | 	// from dest to src also 
34 | 	graph->adjList[dest].insert(src); 
35 | } 
36 | 
37 | // A utility function to print the adjacency 
38 | // list representation of graph 
39 | void printGraph(Graph* graph) 
40 | { 
41 | 	for (int i = 0; i < graph->V; ++i) { 
42 | 		set<int, greater<int> > lst = graph->adjList[i]; 
43 | 		cout << endl << "Adjacency list of vertex "
44 | 			<< i << endl; 
45 | 
46 | 		for (auto itr = lst.begin(); itr != lst.end(); ++itr) 
47 | 			cout << *itr << " "; 
48 | 		cout << endl; 
49 | 	} 
50 | } 
51 | 
52 | // Searches for a given edge in the graph 
53 | void searchEdge(Graph* graph, int src, int dest) 
54 | { 
55 | 	auto itr = graph->adjList[src].find(dest); 
56 | 	if (itr == graph->adjList[src].end()) 
57 | 		cout << endl << "Edge from " << src 
58 | 			<< " to " << dest << " not found."
59 | 			<< endl; 
60 | 	else
61 | 		cout << endl << "Edge from " << src 
62 | 			<< " to " << dest << " found."
63 | 			<< endl; 
64 | } 
65 | 
66 | // Driver code 
67 | int main() 
68 | { 
69 | 	// Create the graph given in the above figure 
70 | 	int V = 5; 
71 | 	struct Graph* graph = createGraph(V); 
72 | 	addEdge(graph, 0, 1); 
73 | 	addEdge(graph, 0, 4); 
74 | 	addEdge(graph, 1, 2); 
75 | 	addEdge(graph, 1, 3); 
76 | 	addEdge(graph, 1, 4); 
77 | 	addEdge(graph, 2, 3); 
78 | 	addEdge(graph, 3, 4); 
79 | 
80 | 	// Print the adjacency list representation of 
81 | 	// the above graph 
82 | 	printGraph(graph); 
83 | 
84 | 	// Search the given edge in the graph 
85 | 	searchEdge(graph, 2, 1); 
86 | 	searchEdge(graph, 0, 3); 
87 | 
88 | 	return 0; 
89 | }
90 | 


--------------------------------------------------------------------------------
/Graph/Graph Prims.cpp:
--------------------------------------------------------------------------------
  1 | #include<bits/stdc++.h>
  2 | using namespace std;
  3 | #define I INT_MAX
  4 | #define MAX 100
  5 | 
  6 | int near[MAX] = {I};
  7 | int t[2][MAX];
  8 | int Cost[MAX][MAX];
  9 | 
 10 | int main()
 11 | {
 12 | 
 13 | 
 14 |     int vertex_count,data,total_weight = 0;
 15 |     cout<<"Enter the number of vertex:- ";
 16 |     cin>>vertex_count;
 17 | 
 18 | 
 19 |     memset(near, I , sizeof(near));
 20 |     /**********INPUT VALUES***********/
 21 | 
 22 | 
 23 |     for(int i=1; i <= vertex_count;i++)
 24 |         for(int j=1; j <= vertex_count;j++)
 25 |         {
 26 |             cout<<"If there is edge between "<<i<<" and "<<j<<" Enter it's weight else press 0: ";
 27 |             cin>>data;
 28 |             if(data!=0)
 29 |                 Cost[i][j] = data;
 30 |             else
 31 |                 Cost[i][j] = I;
 32 | 
 33 |         }
 34 | 
 35 |      /**********INITIAL STEP***********/
 36 | 
 37 | 
 38 |      int minimum = I,u,v;
 39 |         for(int i=1;i<vertex_count+1;i++)
 40 |         for(int j=i;j<vertex_count+1;j++)       //here j = i because its values are same as they are repeating so we can consider only upper triangular matrix
 41 |         {
 42 |             if(Cost[i][j] < minimum)
 43 |             {
 44 |                 minimum = Cost[i][j];
 45 |                 u = i;
 46 |                 v = j;
 47 |             }
 48 |         }
 49 | 
 50 |      t[0][0] = u;
 51 |      t[1][0] = v;
 52 | 
 53 |      total_weight += Cost[u][v];
 54 | 
 55 |      near[u] = 0;
 56 |      near[v] = 0;
 57 | 
 58 |      //Now lets update near array
 59 | 
 60 |      for(int i=1; i <= vertex_count ; i++)
 61 |      {
 62 |         if(near[i] != 0)
 63 |         {
 64 |             if(Cost[i][u] < Cost[i][v])
 65 |                 near[i] = u;
 66 |             else
 67 |                 near[i] = v;
 68 |         }
 69 |      }
 70 | 
 71 |     /**********REPEATING STEP***********/
 72 |     int k,j;
 73 |     for(int i=1 ; i < vertex_count-1 ;i++)
 74 |     {
 75 |         minimum = I;
 76 |         for(j = 1 ; j <= vertex_count ; j++)
 77 |         {
 78 |             if((near[j] != 0) and (Cost[j][near[j]] < minimum))
 79 |             {
 80 |                 minimum = Cost[j][near[j]];
 81 |                 k = j;
 82 |             }
 83 |         }
 84 | 
 85 |         total_weight += Cost[k][near[k]];
 86 |         t[0][i] = k;
 87 |         t[1][i] = near[k];
 88 |         near[k] = 0;
 89 | 
 90 |         //update near array
 91 | 
 92 |         for(int j = 1 ; j <= vertex_count ; j++)
 93 |         {
 94 |             if((near[j] != 0) && (Cost[j][k] < Cost[j][near[j]]))
 95 |             near[j] = k;
 96 |         }
 97 |     }
 98 | 
 99 |     for(int i = 0; i < vertex_count-1; i++)
100 |         cout<<t[0][i]<<"  "<<t[1][i]<<endl;
101 | 
102 |     cout<<"\nTotal weight: "<<total_weight<<endl;
103 | 
104 | return 0;
105 | }
106 | 


--------------------------------------------------------------------------------
/Linked List/CircularLinkedList.cpp:
--------------------------------------------------------------------------------
  1 | #include<iostream>
  2 | using namespace std;
  3 | struct Node
  4 | {
  5 | 	
  6 | 	int data;
  7 | 	Node *next;
  8 | }*head=NULL;
  9 | 
 10 | void create(int arr[],int size)
 11 | {
 12 | 	head = new Node;
 13 | 	Node *p = head;	
 14 | 	
 15 | 	head->data = arr[0];
 16 | 	head->next=head;
 17 | 	Node *temp;
 18 | 
 19 | 	for(int i=1;i<size;++i)
 20 | 	{
 21 | 		temp = new Node;
 22 | 		
 23 | 		temp->data = arr[i];
 24 | 		p->next = temp;
 25 | 		temp->next=head;
 26 | 		p=temp; // this is used to move p to next node		
 27 | 			
 28 | 	}
 29 | 	
 30 | }
 31 | void display()
 32 | {
 33 | 	Node *p = head;
 34 | 	do{		
 35 | 		cout<<p->data<<" ";
 36 | 		p=p->next;
 37 | 	}while(p!=head);
 38 | }
 39 | 
 40 | void insert()
 41 | {
 42 | 	cout<<"On Which index you want to insert : ";
 43 | 	int it;
 44 | 	cin>>it;
 45 | 	int d;	
 46 | 	int cnt=0;
 47 | 	Node *p=head;
 48 | 	if(it==0)     //first node insertion
 49 | 	{
 50 | 		if(head==NULL)
 51 | 		{
 52 | 			cout<<"***FIRSTLY CREATE THE NODE***\n";		
 53 | 		}else{
 54 | 		Node *temp=new Node;	
 55 | 		cout<<"Enter the data you want to insert : ";
 56 | 		cin>>d;		
 57 | 		temp->data=d;
 58 | 		while(p->next!=head)
 59 | 		{
 60 | 			p=p->next;
 61 | 		}	
 62 | 		temp->next=p->next;		
 63 | 		p->next=temp;	
 64 | 		head=temp;}	
 65 | 	}else // insertion at any place
 66 | 	{
 67 | 		if(head==NULL)
 68 | 		{
 69 | 			cout<<"***FIRSTLY CREATE THE NODE***\n";		
 70 | 		}else{
 71 | 		Node *temp=new Node;		
 72 | 		cout<<"Enter the data you want to insert : ";
 73 | 		cin>>d;		
 74 | 		cout<<"After which data you want to insert : ";
 75 | 		int da;		
 76 | 		cin>>da;		
 77 | 		temp->data=d;			
 78 | 		while(da!=p->data)
 79 | 		{
 80 | 			p=p->next;
 81 | 			cnt++;	
 82 | 		}		
 83 | 		temp->next=p->next;
 84 | 		p->next=temp;}
 85 | 	}
 86 | }
 87 | 
 88 | void deleteNode()
 89 | {
 90 | 	cout<<"Enter the data of Node which you want to delete :";
 91 | 	int d;
 92 | 	cin>>d;
 93 | 	Node *p1=head;
 94 | 	Node *p2=NULL;	
 95 | 	if(head==NULL)
 96 | 	{
 97 | 		cout<<"Insert Node First\n";
 98 | 	}
 99 | 	else{
100 | 	if(d==head->data)	// delete first node
101 | 	{
102 | 		while(p1->next!=head)
103 | 		{
104 | 			p1=p1->next;
105 | 		}		
106 | 		p1->next=head->next;
107 | 		head=head->next;
108 | 	}else			// dlete any node
109 | 	{
110 | 		while(p1->data!=d)
111 | 		{
112 | 			p2=p1;
113 | 			p1=p1->next;
114 | 		}
115 | 		p2->next=p1->next;
116 | 	}
117 | 	}
118 | }
119 | 
120 | int main()
121 | {
122 | 	int arr[] = {100,200,300,400,500};
123 | 	int ch;	
124 | 	cout<<"*************************CIRCULAR LINKED LIST********************************";	
125 | 	while(ch!=5)
126 | 	{
127 | 	cout<<"\n1) Create \n2) display \n3) insert \n4) delete\n5) exit \n";
128 | 	cin>>ch;
129 | 	switch(ch)
130 | 	{
131 | 		case 1:create(arr,5);
132 | 			break;
133 | 		case 2:display();
134 | 			break;
135 | 		case 3:insert();
136 | 			break;	
137 | 		case 4:deleteNode();
138 | 			break;
139 | 		case 5:exit(1); 
140 | 	}
141 | 	}
142 | }
143 | 


--------------------------------------------------------------------------------
/Heaps/Heap- MIN and MAX.cpp:
--------------------------------------------------------------------------------
  1 | #include <bits/stdc++.h>
  2 | using namespace std;
  3 | #define MAX 100
  4 | 
  5 | int maxheap[MAX], minheap[MAX];
  6 | 
  7 | 
  8 |     void maxinsert(int index)
  9 |     {
 10 |         int temp = maxheap[index];
 11 |         while(( index > 1) and (temp > maxheap[index/2]))
 12 |         {
 13 |             maxheap[index] = maxheap[index/2];
 14 |             index = index/2;
 15 |         }
 16 |         maxheap[index] = temp;
 17 |     }
 18 | 
 19 |     void mininsert(int index)
 20 |     {
 21 |         int temp = minheap[index];
 22 |         while(( index > 1 ) and (temp < minheap[index/2]))
 23 |         {
 24 |             minheap[index] = minheap[index/2];
 25 |             index = index/2;
 26 |         }
 27 |         minheap[index] = temp;
 28 |     }
 29 | 
 30 |     void display(int len)
 31 |     {
 32 |         cout<<"\n========================================\n";
 33 |         cout<<"MAX HEAP: ";
 34 |         for(int i=1; i < len; i++)
 35 |             cout<<maxheap[i]<<" ";
 36 |         cout<<endl;
 37 | 
 38 |         cout<<"MIN HEAP: ";
 39 |         for(int i=1; i < len; i++)
 40 |             cout<<minheap[i]<<" ";
 41 |         cout<<"\n========================================";
 42 |     }
 43 | int main()
 44 | {
 45 |     int len,data;
 46 |     cout<<"Enter the number of elements to be entered in Heap: ";
 47 |     cin>>len;
 48 |     /****Initialise the array*****/
 49 |     maxheap[0] = 0;
 50 |     minheap[0] = 0;
 51 |     for(int i=1;i <= len; i++)
 52 |     {
 53 |         cout<<"Enter "<<i<<" element: ";
 54 |         cin>>data;
 55 |         maxheap[i] = data;
 56 |         minheap[i] = data;
 57 |     }
 58 | 
 59 |     /*******Organising each element properly in heap******/
 60 |     for(int i=2;i<=len;i++)
 61 |     {
 62 |        maxinsert(i);
 63 |        mininsert(i);
 64 |     }
 65 | 
 66 |     int newindex = len+1;
 67 |     int choice;
 68 | 
 69 | 
 70 |     /*******Printing the MAX Heap Generated**********/
 71 | 
 72 |     display(newindex);
 73 | 
 74 |     while(1)
 75 |     {
 76 |         cout<<"\nPress 1 to insert a new number: ";
 77 |         cout<<"\nPress 2 to Display: ";
 78 |         cout<<"\nPress 3 to Exit: ";
 79 |         cout<<"\nEnter your choice: ";
 80 |         cin>>choice;
 81 | 
 82 |         switch(choice)
 83 |         {
 84 |             case 1: cout<<"Enter "<<newindex<<" element: ";
 85 |                     cin>>data;
 86 |                     maxheap[newindex] = data;
 87 |                     minheap[newindex] = data;
 88 |                     maxinsert(newindex);
 89 |                     mininsert(newindex);
 90 |                     newindex++;
 91 |                     break;
 92 | 
 93 |             case 2: display(newindex);
 94 |                     break;
 95 | 
 96 |             case 3: return 0;
 97 | 
 98 |             default: cout<<"Enter a valid choice !"<<endl;
 99 |         }
100 |     }
101 | }
102 | 


--------------------------------------------------------------------------------
/Linked List/DoublyLinkedList.cpp:
--------------------------------------------------------------------------------
  1 | // Circular Doubly Linked List is also similar to Doubly Linked List Only differnnce is that Last node next is pointing to first node and first node previous is pointing to last node so IN ORDER TO REACH LAST NODE YOU DONT NEED TO TRAVERSE ALL NODES jiust tpe the code head->prev
  2 | #include<iostream>
  3 | using namespace std;
  4 | struct Node
  5 | {
  6 | 	int data;
  7 | 	Node *prev,*next;
  8 | }*head=NULL;
  9 | 
 10 | void create(int arr[],int size)
 11 | {
 12 | 	head = new Node;
 13 | 	head->data=arr[0];
 14 | 	head->prev=head->next=NULL;
 15 | 	Node *p=head;
 16 | 	for(int i=1;i<size;++i)
 17 | 	{
 18 | 		Node *temp=new Node;
 19 | 		temp->data=arr[i];
 20 | 		temp->next=p->next;
 21 | 		temp->prev=p;
 22 | 		p->next=temp;
 23 | 		p=temp;
 24 | 	}
 25 | }
 26 | 
 27 | void display()
 28 | {
 29 | 	Node *ptr=head;
 30 | 	while(ptr)
 31 | 	{
 32 | 		cout<<ptr->data<<" ";
 33 | 		ptr=ptr->next;	
 34 | 	}
 35 | }
 36 | 
 37 | void length()
 38 | {
 39 | 	int cnt = 0;
 40 | 	Node *p1=head;
 41 | 	while(p1)
 42 | 	{
 43 | 		++cnt;
 44 | 		p1=p1->next;
 45 | 	}
 46 | 	cout<<"Length : "<<cnt<<"\n";
 47 | }
 48 | 
 49 | void insert()
 50 | {
 51 | 	Node *p=head;
 52 | 	cout<<"Enter the data after which you want to insert new node : ";
 53 | 	int d;
 54 | 	cin>>d;
 55 | 	cout<<"Enter the New Node data : ";
 56 | 	int da;
 57 | 	cin>>da;
 58 | 	Node *temp=new Node;
 59 | 	temp->data=da;
 60 | 	Node*p2=NULL;
 61 | 
 62 | 	{
 63 | 		while(p->data!=d )
 64 | 		{
 65 | 			p=p->next;
 66 | 		}		
 67 | 		temp->next=p->next;
 68 | 		temp->prev=p;
 69 | 		if(p->next!=NULL)		// Checking whether the next node is present or not
 70 | 		p->next->prev=temp;
 71 | 		p->next=temp;
 72 | 	}
 73 | 	
 74 | }
 75 | 
 76 | void firstNode()
 77 | {
 78 | 	Node *p= head;
 79 | 	cout<<"Enter the New Node data : ";
 80 | 	int da;
 81 | 	cin>>da;
 82 | 	Node *temp=new Node;
 83 | 	temp->data=da;
 84 | 	
 85 | 	temp->next=p;
 86 | 	temp->prev=p->prev;
 87 | 	p->prev=temp;
 88 | 	
 89 | 	head=temp;
 90 | }
 91 | 
 92 | void deleteNode()
 93 | {
 94 | 	Node *p1= head;
 95 | 	cout<<"Enter the Node data which you want to delete : ";
 96 | 	int da;
 97 | 	cin>>da;
 98 | 	Node *p2=NULL;
 99 | 	if(head->data==da)
100 | 	{
101 | 		if(head->next!=NULL)
102 | 		{
103 | 			head->next->prev=NULL;
104 | 			head=head->next;
105 | 		}		
106 | 	}else
107 | 	{
108 | 		while(p1->data!=da)
109 | 		{
110 | 			p2=p1;
111 | 			p1=p1->next;
112 | 		}
113 | 		p2->next=p1->next;
114 | 		if(p1->next!=NULL)	// Condition for last node that next node is NULL or NOT
115 | 		p1->next->prev=p2;
116 | 	}
117 | }
118 | 
119 | void reverse()
120 | {
121 | 	Node *p1=head;
122 | 	while(p1->next!=NULL)
123 | 	{
124 | 		p1=p1->next;
125 | 	}	
126 | 	while(p1!=NULL)
127 | 	{
128 | 		cout<<p1->data<<" ";	
129 | 		p1=p1->prev;
130 | 	}
131 | 	
132 | }
133 | 
134 | int main()
135 | {
136 | 	int arr[] = {1000,2000,3000,4000,5000};
137 | 	cout<<"*************************DOUBLY LINKED LIST********************************";	
138 | 	int ch;	
139 | 	while(ch!=7)
140 | 	{
141 | 		cout<<"\n1) Create \n2) display \n3) Length \n4) Insert\n5) Insert at First \n6) Delete any Node \n7) Reverse\n";
142 | 		cin>>ch;
143 | 		switch(ch)
144 | 		{
145 | 		 	case 1: create(arr,5);
146 | 				break;	
147 | 			case 2: display();
148 | 				break;
149 | 			case 3: length();
150 | 				break;	
151 | 			case 4: insert();
152 | 				break;
153 | 			case 5: firstNode();
154 | 				break;
155 | 			case 6: deleteNode();
156 | 				break;	
157 | 			case 7: reverse();	
158 | 		}
159 | 	}
160 | }
161 | 


--------------------------------------------------------------------------------
/Stack/stack-using-queue.cpp:
--------------------------------------------------------------------------------
  1 | /**
  2 |  * @file
  3 |  * @brief Implement a last in first out (LIFO) stack using queues. The implemented stack should support all the functions of a normal queue (push, top, pop, and empty).
  4 |  * @author [Neha Labhasetwar](https://github.com/nehalabhasetwar)
  5 |  */
  6 | 
  7 | #include <iostream>  // for standard IO operations
  8 | #include <cassert>   // defines one macro function (assert) that can be used as a standard debugging tool
  9 | #include <queue>     // This header is part of the containers library, designed to operate in FIFO context
 10 | 
 11 | namespace stack_using_queue {
 12 | /**
 13 |  * @brief Assuming we already have a class implemented for Queue, we will first design the class for Stack.
 14 |  * It will have the methods push() , pop() , top() , and empty() and one queue.
 15 |  */
 16 | class MyStack
 17 | {
 18 |     /** initialize queue */
 19 |     std::queue <int> q;      //empty queue q of int type
 20 | 
 21 |     public:
 22 | 
 23 |     MyStack() = default;                                 //default constructor for stack
 24 | 
 25 | /**
 26 |  * @brief Function to Push element onto stack
 27 |  * @param x number to be pushed
 28 |  * @returns void
 29 |  */
 30 |     void push(int x)
 31 |     {
 32 |         q.push(x);                                  //let's assume x=3,queue=1,2 , then queue will become 1,2,3
 33 |         int s=q.size();                             //get size of queue
 34 |         for(int i=0;i<s-1;i++)                      //here we will invert queue (1,2,3 -> 2,3,1 -> 3,1,2)
 35 |         {
 36 |             int y=q.front();                        //because if we want to remove from stack so our element should be at front in queue
 37 |             q.pop();
 38 |             q.push(y);
 39 |         }
 40 |     }
 41 | /**
 42 |  * @brief Function to Remove the element on top of the stack and return that element.
 43 |  * @returns element that is deleted from the stack
 44 |  */
 45 |     int pop()
 46 |     {
 47 |         int y=q.front();
 48 |         q.pop();
 49 |         return y;
 50 |     }
 51 | /**
 52 |  * @brief Function to Get the topmost element from stack.
 53 |  * @returns element on the top of stack
 54 |  */
 55 |     int top()
 56 |     {
 57 |         return q.front();
 58 |     }
 59 | /**
 60 |  * @brief Function to Return whether the stack is empty.
 61 |  * @return if stack is empty, returns true, else false
 62 |  */
 63 |     bool empty()
 64 |     {
 65 |         return q.empty();
 66 |     }
 67 | };
 68 | } // namespace stack_using_queue
 69 | 
 70 | /**
 71 |  * @brief Test Implementations
 72 |  * @returns void
 73 |  */
 74 | static void tests()
 75 | {
 76 |     stack_using_queue::MyStack obj;            //  object of stack_using_queue::MyStack class
 77 | 
 78 |     std::cout << "Test #1\n";
 79 |     obj.push(2);
 80 |     obj.push(5);
 81 |     obj.push(0);
 82 |     assert(obj.top() == 0);
 83 |     assert(obj.pop() == 0);
 84 |     assert(obj.top() == 5);
 85 |     assert(obj.pop() == 5);
 86 |     assert(obj.top() == 2);
 87 |     assert(obj.pop() == 2);
 88 |     assert(obj.empty() == true);
 89 |     std::cout << "PASSED TEST 1\n";
 90 | 
 91 |     std::cout << "Test #2\n";
 92 |     obj.push(-1);
 93 |     assert(obj.empty() == false);
 94 |     assert(obj.top() == -1);
 95 |     assert(obj.pop() == -1);
 96 |     std::cout << "PASSED TEST 2\n";
 97 | }
 98 | /**
 99 |  * @brief Main function calling tests function
100 |  * @returns 0 on exit
101 |  */
102 | int main()
103 | {
104 |     tests(); // Execute the Tests
105 |     return 0;
106 | }
107 | 


--------------------------------------------------------------------------------
/Hashing:
--------------------------------------------------------------------------------
  1 | #include<iostream>
  2 | #include<stdlib.h>
  3 | #include<string.h>
  4 | 
  5 | using namespace std;
  6 | 
  7 | typedef struct Dictionary
  8 | {
  9 |   char word[20];
 10 |   char meaning[20];
 11 | }dict;
 12 | 
 13 | 
 14 | class Hashing
 15 | {
 16 |         dict hashtable[26];
 17 | 
 18 |        public:
 19 | 
 20 |        int hashfun(char w[20])
 21 |        {
 22 |               int key=0;
 23 |               if(w[0]>='A' && w[0]<='Z')
 24 |               key=w[0]-65;
 25 |               else if(w[0]>='a' && w[0]<='z')
 26 |               key=w[0]-97;
 27 | 
 28 |               return key;
 29 |        }
 30 | 
 31 |        Hashing()
 32 |        {
 33 |               for(int i=0;i<=26;i++)
 34 |               {
 35 |                      strcpy(hashtable[i].word,"");
 36 |                      strcpy(hashtable[i].meaning,"");
 37 |               }
 38 |        }
 39 | 
 40 |   void readData()
 41 |   {
 42 |        dict temp;
 43 |      
 44 |      
 45 | 
 46 |        cout<<"\nEnter word : ";
 47 |        cin>>temp.word;
 48 |        cout<<"\nEnter meaning : ";
 49 |        cin>>temp.meaning;
 50 | 
 51 |        int key=hashfun(temp.word);
 52 |        assign(temp,key);
 53 |        cout<<"\nInserted successfully";
 54 |      
 55 |        cout<<"\nkey is : "<<key;
 56 |     
 57 |   }
 58 | 
 59 | 
 60 |   void assign(dict temp,int hkey)
 61 |   {
 62 |     int flag=0;
 63 | 
 64 |        if(strcmp(hashtable[hkey].word,"")==0)
 65 |        {
 66 | 	       hashtable[hkey]=temp;
 67 | 	        flag=1;
 68 | 	       return ;
 69 |        }
 70 | 
 71 |         for(int i=hkey+1;i<26;i++)
 72 | 	{
 73 | 	       if(strcmp(hashtable[i].word,"")==0)
 74 | 	       {
 75 | 	              hashtable[i]=temp;
 76 | 	               flag=1;
 77 | 	              return;
 78 | 	       }
 79 | 	}
 80 |       if(flag==0)
 81 |       {
 82 | 	       for(int i=0;i<hkey;i++)
 83 | 	       {
 84 | 	              if(strcmp(hashtable[i].word,"")==0)
 85 | 	              {
 86 | 	                     hashtable[i]=temp;
 87 | 	                      return;
 88 | 	              }
 89 | 	       }
 90 |       }
 91 | 
 92 |   }
 93 | 
 94 |   void display()
 95 |   {
 96 |        cout<<"\n\nKey \t\tWord\tMeaning";
 97 |        for(int i=0;i<26;i++)
 98 |       {
 99 |               cout<<"\n"<<i<<"\t\t"<<hashtable[i].word<<"\t"<<hashtable[i].meaning;
100 |       }
101 |   }
102 | 
103 |   int search(char w[20])
104 |   {
105 |        int k=hashfun(w);
106 |        if(strcmp(hashtable[k].word,w)==0)
107 |       {
108 | 	       cout<<"\nMeaning : "<<hashtable[k].meaning;
109 | 	       return 1;
110 |       }
111 |    /* for(int i=k+1;i!=k;i=(i+1)%26)
112 |     {
113 |      if(strcmp(hashtable[i].word,w)==0)
114 |       {
115 | 	cout<<"Meaning "<<hashtable[i].meaning;
116 | 	return 1;
117 |       }
118 |     }*/
119 | 
120 |     return 0;
121 | 
122 |   }
123 | 
124 | 
125 | };
126 | int main()
127 | {
128 |        int ch;
129 |        char w[20];      
130 |         Hashing h;
131 |        do
132 |        {
133 |        cout<<"\nMenu";
134 |        cout<<"\n1.Insert";
135 |        cout<<"\n2.Search";
136 |        cout<<"\n3.Display";
137 |        cout<<"\n4.Exit";
138 |        cout<<"\nEnter your choice : ";
139 |        cin>>ch;
140 |        switch(ch)
141 |        {
142 |        case 1:
143 |        h.readData();
144 |        break;
145 |        
146 |        case 2:
147 |        cout<<"Enter a word to be search : ";
148 |        cin>>w;
149 |        //h.search(w);
150 |        if(!h.search(w))
151 |        cout<<"\nNo such word present";
152 |        break;
153 |        
154 |        case 3:
155 |        h.display();
156 |        break;
157 |        case 4:
158 |        
159 |        exit(0);
160 |        break;
161 |        }
162 |        }while(ch!=4);
163 |        return 0;
164 | }
165 | 
166 | 


--------------------------------------------------------------------------------
/Segment Tree/segmenttree(max).cpp:
--------------------------------------------------------------------------------
  1 | #include<bits/stdc++.h>
  2 | using namespace std;
  3 | 
  4 | void buildtree(int *tree,int *a, int index, int s, int e)
  5 | {
  6 | 
  7 | 	//base case
  8 | 	if(s > e)
  9 | 		return;
 10 | 
 11 | 	//base class leaf node
 12 | 	if(s == e)
 13 | 	{
 14 | 		tree[index] = a[s];
 15 | 		return;
 16 | 	}
 17 | 	
 18 | 	//recursive case
 19 | 	int mid = (s + e)/2;
 20 | 
 21 | 	//build left sub tree
 22 | 	buildtree(tree,a,2*index,s, mid);
 23 | 	
 24 | 	//build right sub tree
 25 | 	buildtree(tree, a, 2*index+1, mid+1, e);
 26 | 	
 27 | 	//getting min value
 28 | 	int left = tree[2*index];
 29 | 	int right = tree[2*index + 1];
 30 | 
 31 | 	tree[index] = min(left, right);
 32 | 	
 33 | }
 34 | 
 35 | int query(int *tree,int index, int s, int e, int qs, int qe)
 36 | {
 37 | 	//complete overlap condition
 38 | 	if(qs <= s and qe >= e)
 39 | 		return tree[index];
 40 | 
 41 | 	//No overlap condition
 42 | 	if(qe < s or qs > e)
 43 | 		return INT_MIN;
 44 | 
 45 | 	//Partial Overlap
 46 | 	int mid = (s+e)/2;
 47 | 	//getting results from left and right
 48 | 	int left = query(tree, index*2, s, mid,qs,qe);
 49 | 	int right = query(tree, index*2+1, mid+1, e,qs,qe);
 50 | 
 51 | 	//returning the minimum one
 52 | 	return max(left, right);
 53 | }
 54 | 
 55 | //to update a single node
 56 | void updatenode(int *tree, int index, int s, int e, int i, int val)
 57 | {
 58 | 	//no overlap
 59 | 	if(i < s or i > e)
 60 | 		return;
 61 | 
 62 | 	//reached leaf node
 63 | 	if(s == e)
 64 | 	{
 65 | 		tree[index] = val;
 66 | 		return;
 67 | 	}
 68 | 
 69 | 	//partial overlap (i.e.  i is lying between s and e)
 70 | 	int mid = (s + e)/2;
 71 | 	updatenode(tree, 2*index, s, mid, i, val);
 72 | 	updatenode(tree, 2*index + 1, mid + 1, e, i, val);	
 73 | 
 74 | 	//updating parent nodes
 75 | 	tree[index] = max(tree[2*index], tree[2*index + 1]);
 76 | 
 77 | 	return;
 78 | }
 79 | 
 80 | //incrementing a range with a particular value
 81 | void updaterange(int *tree, int index, int s, int e, int rs, int re, int inc)
 82 | {
 83 | 
 84 | 	//no overlap
 85 | 	if(re < s or rs > e)
 86 | 		return;
 87 | 
 88 | 	if(s==e)
 89 | 	{
 90 | 		tree[index] += inc;
 91 | 		return;
 92 | 	}
 93 | 
 94 | 	int mid = (s + e)/2;
 95 | 	updaterange(tree, 2*index, s, mid, rs, re, inc);
 96 | 	updaterange(tree, 2*index + 1, mid + 1, e, rs, re, inc);	
 97 | 
 98 | 	//updating parent nodes
 99 | 	tree[index] = max(tree[2*index], tree[2*index + 1]);
100 | 	return;
101 | }
102 | 
103 | 
104 | int main()
105 | {
106 | 	int n;
107 | 	cout<<"Enter the no. of elements: ";
108 | 	cin>>n;
109 | 	int a[n];
110 | 	for(int i=0; i<n; i++)
111 | 	{
112 | 		cout<<"Enter "<<i+1<<" element: ";
113 | 		cin>>a[i];
114 | 	}
115 | 	//starting and ending values
116 | 	int s = 0;
117 | 	int e = n-1;
118 | 
119 | 
120 | 	//making a tree array of size(4*n + 1).[4*n + 1 is an upper bound]
121 | 	int tree[(4*n) + 1];
122 | 
123 | 	//building the tree
124 | 	buildtree(tree, a, 1, s, e);
125 | 
126 | 	int q;
127 | 	cout<<"Enter the number of queries: ";
128 | 	cin>>q;
129 |     
130 |     int l, r, i, val;
131 | 	
132 | 	while(q--)
133 | 	{
134 | 		int ch;
135 | 		cout<<"Press 1 to get the maximum value between a range"<<endl;
136 | 		cout<<"Press 2 to update a particular value"<<endl;
137 | 		cout<<"Press 3 to increment a range"<<endl;
138 | 		cout<<"Press 4 to exit"<<endl;
139 | 		cin>>ch;
140 |        
141 | 		switch(ch)
142 | 		{
143 | 			case 1: cout<<"Range starts from (0 based indexing): ";
144 | 					cin>>l;
145 | 					cout<<"Range ends at (0 based indexing): ";
146 | 					cin>>r;
147 | 					cout<<"maximum number in range  "<<l<<" - "<<r<<"  is: "<<query(tree, 1, s, e, l, r)<<endl;
148 | 					break;
149 | 
150 | 			case 2: cout<<"Enter the index to be changed(0 based indexing): ";
151 | 					cin>>i;
152 | 					cout<<"Enter the updated value: ";
153 | 					cin>>val;
154 | 					updatenode(tree, 1, s, e, i, val);
155 | 					cout<<"value updated successfully."<<endl;
156 | 					break;		
157 | 
158 | 			case 3: cout<<"Range starts from (0 based indexing): ";
159 | 					cin>>l;
160 | 					cout<<"Range ends at (0 based indexing): ";
161 | 					cin>>r;
162 | 					cout<<"Range updated from  "<<l<<" - "<<r<<"  successfully."<<endl;
163 | 					break;
164 | 
165 | 			case 4:	return 0;
166 | 			
167 | 			default: cout<<"Please enter a valid option"<<endl;		
168 | 		}
169 | 		
170 | 	}
171 | 		
172 | 	return 0;
173 | }


--------------------------------------------------------------------------------
/Segment Tree/segmenttree.cpp:
--------------------------------------------------------------------------------
  1 | #include<bits/stdc++.h>
  2 | using namespace std;
  3 | 
  4 | void buildtree(int *tree,int *a, int index, int s, int e)
  5 | {
  6 | 
  7 | 	//base case
  8 | 	if(s > e)
  9 | 		return;
 10 | 
 11 | 	//base class leaf node
 12 | 	if(s == e)
 13 | 	{
 14 | 		tree[index] = a[s];
 15 | 		return;
 16 | 	}
 17 | 	
 18 | 	//recursive case
 19 | 	int mid = (s + e)/2;
 20 | 
 21 | 	//build left sub tree
 22 | 	buildtree(tree,a,2*index,s, mid);
 23 | 	
 24 | 	//build right sub tree
 25 | 	buildtree(tree, a, 2*index+1, mid+1, e);
 26 | 	
 27 | 	//getting min value
 28 | 	int left = tree[2*index];
 29 | 	int right = tree[2*index + 1];
 30 | 
 31 | 	tree[index] = min(left, right);
 32 | 	
 33 | }
 34 | 
 35 | int query(int *tree,int index, int s, int e, int qs, int qe)
 36 | {
 37 | 	//complete overlap condition
 38 | 	if(qs <= s and qe >= e)
 39 | 		return tree[index];
 40 | 
 41 | 	//No overlap condition
 42 | 	if(qe < s or qs > e)
 43 | 		return INT_MAX;
 44 | 
 45 | 	//Partial Overlap
 46 | 	int mid = (s+e)/2;
 47 | 	//getting results from left and right
 48 | 	int left = query(tree, index*2, s, mid,qs,qe);
 49 | 	int right = query(tree, index*2+1, mid+1, e,qs,qe);
 50 | 
 51 | 	//returning the minimum one
 52 | 	return min(left, right);
 53 | }
 54 | 
 55 | //to update a single node
 56 | void updatenode(int *tree, int index, int s, int e, int i, int val)
 57 | {
 58 | 	//no overlap
 59 | 	if(i < s or i > e)
 60 | 		return;
 61 | 
 62 | 	//reached leaf node
 63 | 	if(s == e)
 64 | 	{
 65 | 		tree[index] = val;
 66 | 		return;
 67 | 	}
 68 | 
 69 | 	//partial overlap (i.e.  i is lying between s and e)
 70 | 	int mid = (s + e)/2;
 71 | 	updatenode(tree, 2*index, s, mid, i, val);
 72 | 	updatenode(tree, 2*index + 1, mid + 1, e, i, val);	
 73 | 
 74 | 	//updating parent nodes
 75 | 	tree[index] = min(tree[2*index], tree[2*index + 1]);
 76 | 
 77 | 	return;
 78 | }
 79 | 
 80 | //incrementing a range with a particular value
 81 | void updaterange(int *tree, int index, int s, int e, int rs, int re, int inc)
 82 | {
 83 | 
 84 | 	//no overlap
 85 | 	if(re < s or rs > e)
 86 | 		return;
 87 | 
 88 | 	if(s==e)
 89 | 	{
 90 | 		tree[index] += inc;
 91 | 		return;
 92 | 	}
 93 | 
 94 | 	int mid = (s + e)/2;
 95 | 	updaterange(tree, 2*index, s, mid, rs, re, inc);
 96 | 	updaterange(tree, 2*index + 1, mid + 1, e, rs, re, inc);	
 97 | 
 98 | 	//updating parent nodes
 99 | 	tree[index] = min(tree[2*index], tree[2*index + 1]);
100 | 	return;
101 | }
102 | 
103 | 
104 | int main()
105 | {
106 | 	int n;
107 | 	cout<<"Enter the no. of elements: ";
108 | 	cin>>n;
109 | 	int a[n];
110 | 	for(int i=0; i<n; i++)
111 | 	{
112 | 		cout<<"Enter "<<i+1<<" element: ";
113 | 		cin>>a[i];
114 | 	}
115 | 	//starting and ending values
116 | 	int s = 0;
117 | 	int e = n-1;
118 | 
119 | 
120 | 	//making a tree array of size(4*n + 1).[4*n + 1 is an upper bound]
121 | 	int tree[(4*n) + 1];
122 | 
123 | 	//building the tree
124 | 	buildtree(tree, a, 1, s, e);
125 | 
126 | 	int q;
127 | 	cout<<"Enter the number of queries: ";
128 | 	cin>>q;
129 |     
130 |     int l, r, i, val;
131 | 	
132 | 	while(q--)
133 | 	{
134 | 		int ch;
135 | 		cout<<"Press 1 to get the minimum value between a range"<<endl;
136 | 		cout<<"Press 2 to update a particular value"<<endl;
137 | 		cout<<"Press 3 to increment a range"<<endl;
138 | 		cout<<"Press 4 to exit"<<endl;
139 | 		cin>>ch;
140 |        
141 | 		switch(ch)
142 | 		{
143 | 			case 1: cout<<"Range starts from (0 based indexing): ";
144 | 					cin>>l;
145 | 					cout<<"Range ends at (0 based indexing): ";
146 | 					cin>>r;
147 | 					cout<<"minimum number in range  "<<l<<" - "<<r<<"  is: "<<query(tree, 1, s, e, l, r)<<endl;
148 | 					break;
149 | 
150 | 			case 2: cout<<"Enter the index to be changed(0 based indexing): ";
151 | 					cin>>i;
152 | 					cout<<"Enter the updated value: ";
153 | 					cin>>val;
154 | 					updatenode(tree, 1, s, e, i, val);
155 | 					cout<<"value updated successfully."<<endl;
156 | 					break;		
157 | 
158 | 			case 3: cout<<"Range starts from (0 based indexing): ";
159 | 					cin>>l;
160 | 					cout<<"Range ends at (0 based indexing): ";
161 | 					cin>>r;
162 | 					cout<<"Range updated from  "<<l<<" - "<<r<<"  successfully."<<endl;
163 | 					break;
164 | 
165 | 			case 4:	return 0;
166 | 			
167 | 			default: cout<<"Please enter a valid option"<<endl;		
168 | 		}
169 | 		
170 | 	}
171 | 		
172 | 	return 0;
173 | }
174 | 


--------------------------------------------------------------------------------
/Segment Tree/Segment_tree.cpp:
--------------------------------------------------------------------------------
  1 | //Segment Tree 
  2 | //Updation and Finding sum in given range happens in O(logn)
  3 | #include <bits/stdc++.h> 
  4 | using namespace std; 
  5 |  
  6 | int getMid(int s, int e) { 
  7 |     return s + (e -s)/2; 
  8 | } 
  9 | 
 10 | int getSumUtil(int *st, int ss, int se, int qs, int qe, int si) 
 11 | {
 12 | 	if (qs <= ss && qe >= se) 
 13 | 		return st[si]; 
 14 |  
 15 | 	if (se < qs || ss > qe) 
 16 | 		return 0; 
 17 | 		
 18 | 	int mid = getMid(ss, se); 
 19 | 	return getSumUtil(st, ss, mid, qs, qe, 2*si+1) + 
 20 | 		getSumUtil(st, mid+1, se, qs, qe, 2*si+2); 
 21 | } 
 22 | 
 23 | void updateValueUtil(int *st, int ss, int se, int i, int diff, int si) 
 24 | { 
 25 | 
 26 | 	if (i < ss || i > se) 
 27 | 		return; 
 28 |  
 29 | 	st[si] = st[si] + diff; 
 30 | 	if (se != ss) 
 31 | 	{ 
 32 | 		int mid = getMid(ss, se); 
 33 | 		updateValueUtil(st, ss, mid, i, diff, 2*si + 1); 
 34 | 		updateValueUtil(st, mid+1, se, i, diff, 2*si + 2); 
 35 | 	} 
 36 | } 
 37 |  
 38 | void updateValue(int arr[], int *st, int n, int i, int new_val) 
 39 | { 
 40 | 
 41 | 	if (i < 0 || i > n-1) 
 42 | 	{ 
 43 | 		cout<<"Invalid Input"; 
 44 | 		return; 
 45 | 	} 
 46 | 
 47 | 	int diff = new_val - arr[i]; 
 48 | 
 49 | 	arr[i] = new_val; 
 50 | 
 51 | 	updateValueUtil(st, 0, n-1, i, diff, 0); 
 52 | } 
 53 | 
 54 | int getSum(int *st, int n, int qs, int qe) 
 55 | { 
 56 | 
 57 | 	if (qs < 0 || qe > n-1 || qs > qe) 
 58 | 	{ 
 59 | 		cout<<"Invalid Input"; 
 60 | 		return -1; 
 61 | 	} 
 62 | 
 63 | 	return getSumUtil(st, 0, n-1, qs, qe, 0); 
 64 | } 
 65 | 
 66 | int constructSTUtil(int arr[], int ss, int se, int *st, int si) 
 67 | { 
 68 |  
 69 | 	if (ss == se) 
 70 | 	{ 
 71 | 		st[si] = arr[ss]; 
 72 | 		return arr[ss]; 
 73 | 	} 
 74 |  
 75 | 	int mid = getMid(ss, se); 
 76 | 	st[si] = constructSTUtil(arr, ss, mid, st, si*2+1) + 
 77 | 			constructSTUtil(arr, mid+1, se, st, si*2+2); 
 78 | 	return st[si]; 
 79 | } 
 80 | 
 81 | int *constructST(int arr[], int n) 
 82 | { 
 83 | 
 84 | 	int x = (int)(ceil(log2(n))); 
 85 | 
 86 | 	int max_size = 2*(int)pow(2, x) - 1; 
 87 | 
 88 | 	int *st = new int[max_size]; 
 89 | 
 90 | 	constructSTUtil(arr, 0, n-1, st, 0); 
 91 | 
 92 | 	return st; 
 93 | } 
 94 |  
 95 | int main() 
 96 | { 
 97 |     int *arr , n , i , a , b ;
 98 |     cout << "Enter size of the array" << endl ;
 99 |     cin >> n ;
100 |     arr = new int[n] ;
101 |     cout << "Enter the elements of the array" << endl ;
102 |     for ( i = 0 ; i < n ; i++ )
103 |         cin >> arr[i] ;
104 | 	int *st = constructST(arr, n); 
105 | 	int k = 1 ;
106 | 	do{
107 |         cout << "Enter 1 to find the sum of the values in the given range" << endl ;
108 |         cout << "Enter 2 to update a value in the array" << endl ;
109 |         cout << "Enter 0 to exit" << endl ;
110 |         cout << "Enter your choice" << endl ;
111 |         int k ;
112 |         cin >> k ;
113 |         switch(k){
114 |             case 1 : cout << "Enter the range" << endl ;
115 |                      cin >> a >> b ;
116 |                      cout<<"Sum of values in given range = "<<getSum(st, n, a, b)<<endl;
117 |             break ;
118 |             
119 |             case 2 : cout << "Enter the position to be updated and number to be inserted" << endl ;
120 |                      cin >> a >> b ;
121 |                      updateValue(arr, st, n, a, b);
122 |                      cout << "Updated array is : " ;
123 |                      for ( i = 0 ; i < n ; i++ )
124 |                         cout << arr[i] << " " ;
125 |                      cout << endl ;
126 |             break ;
127 |              
128 |             case 0 : exit(0) ;
129 |         }
130 | 	}
131 | 	while (1);
132 |  
133 | 
134 | 
135 | 	return 0; 
136 | } 
137 | 
138 | /*Sample Output :
139 | Enter size of the array
140 | 5
141 | Enter the elements of the array
142 | 1 3 5 7 9
143 | Enter 1 to find the sum of the values in the given range
144 | Enter 2 to update a value in the array
145 | Enter 0 to exit
146 | Enter your choice
147 | 1
148 | Enter the range
149 | 1 3
150 | Sum of values in given range = 15
151 | Enter 1 to find the sum of the values in the given range
152 | Enter 2 to update a value in the array
153 | Enter 0 to exit
154 | Enter your choice
155 | 2
156 | Enter the position to be updated and number to be inserted
157 | 1 10
158 | Updated array is : 1 10 5 7 9 
159 | Enter 1 to find the sum of the values in the given range
160 | Enter 2 to update a value in the array
161 | Enter 0 to exit
162 | Enter your choice
163 | 1
164 | Enter the range
165 | 1 3
166 | Sum of values in given range = 22
167 | Enter 1 to find the sum of the values in the given range
168 | Enter 2 to update a value in the array
169 | Enter 0 to exit
170 | Enter your choice
171 | 0
172 | */
173 | 
174 | 
175 | 


--------------------------------------------------------------------------------
/Linked List/SinglyLinkedList.cpp:
--------------------------------------------------------------------------------
  1 | // STACK SIZE n+1
  2 | // TIme : O(n)
  3 | // We cannot apply Binary Search in Linked list
  4 | #include<iostream>
  5 | using namespace std;
  6 | struct Node
  7 | {
  8 | 	int rollNo;
  9 | 	string name;
 10 | 	Node *next;		// next is a pointer of node type
 11 | }*head=NULL;		// head is a global pointer
 12 | 
 13 | void insert()
 14 | {
 15 | 	if(head == NULL)
 16 | 	{
 17 | 		head = new Node;	// head is global so we can direct access it
 18 | 		cout<<"Enter RollNo : ";	
 19 | 		int a;
 20 | 		cin>>a;
 21 | 		cout<<"Enter Name : ";
 22 | 		string b;
 23 | 		cin>>b;
 24 | 		head->rollNo = a;
 25 | 		head->name = b;
 26 | 		// head jis node ko point krra hh uska next me NULL dal do
 27 | 		head->next = NULL;
 28 | 	}else
 29 | 	{
 30 | 		Node *temp = new Node;	// temp is pointer which is used for new node creation
 31 | 		cout<<"Enter RollNo : ";	
 32 | 		int c;
 33 | 		cin>>c;
 34 | 		cout<<"Enter Name : ";
 35 | 		string d;
 36 | 		cin>>d;
 37 | 		temp->rollNo = c;
 38 | 		temp->name = d;
 39 | 		Node *p=head;		// p is a pointer which is used only for traversal
 40 | 		while(p->next!=NULL)
 41 | 		{
 42 | 			p = p->next;
 43 | 		}
 44 | 		p->next=temp;
 45 | 		temp->next=NULL;
 46 | 	}
 47 | }
 48 | 
 49 | void count()
 50 | {
 51 | 	int cnt = 0;
 52 | 	Node *pt=head;
 53 | 	while(pt!=NULL)
 54 | 	{
 55 | 		cnt=cnt+1;
 56 | 		pt=pt->next;
 57 | 	}
 58 | 	cout<<"Number of Nodes : "<<cnt<<"\n";
 59 | }
 60 | 
 61 | 
 62 | void display()
 63 | {
 64 | 	Node *pt=head;
 65 | 	cout<<"--------------------------------------------------------------------------\n";
 66 | 	while(pt!=NULL)
 67 | 	{
 68 | 		cout<<"\nName : "<<pt->name<<" "<<"RollNo : "<<pt->rollNo<<"\n";
 69 | 		pt=pt->next;
 70 | 	}
 71 | 	cout<<"--------------------------------------------------------------------------\n";
 72 | }
 73 | 
 74 | void search()
 75 | {
 76 | 	cout<<"Enter the rollNo whose name you want to find : ";
 77 | 	int finds;	
 78 | 	cin>>finds;
 79 | 	Node *pt = head;
 80 | 	if(head==NULL)
 81 | 	{
 82 | 		cout<<"Sorry No element present in List\n";
 83 | 	}
 84 | 	else
 85 | 	{
 86 | 		while(pt->rollNo != finds)
 87 | 		{
 88 | 			pt = pt->next;
 89 | 		}
 90 | 		cout<<"Name : "<<pt->name<<"\n";
 91 | 	}
 92 | }
 93 | void makeFirstNode()
 94 | {
 95 | 	Node *pt = head;
 96 | 	Node *q = NULL;
 97 | 	cout<<"Enter the rollNo whose you want to see in first : ";
 98 | 	int finds;	
 99 | 	cin>>finds;
100 | 	while(pt->rollNo!=finds)
101 | 	{
102 | 		q=pt;
103 | 		pt=pt->next;	
104 | 	}
105 | 	q->next = pt->next;
106 | 	pt->next = head;
107 | 	head = pt;
108 | }
109 | void insertAnywhere()
110 | {
111 | 	cout<<"\nInsert at any Index accept last node\n";
112 | 	
113 | 	Node *ptr = head;
114 | 	Node *temp = new Node;
115 | 	cout<<"Enter Name : ";	
116 | 	string nam;
117 | 	cin>>nam;
118 | 	temp->name=nam;
119 | 	cout<<"Enter RollNo : ";
120 | 	int roll;	
121 | 	cin>>roll;
122 | 	temp->rollNo=roll;
123 | 	int index;
124 | 	cout<<"After which RollNo you want to insert your Node : ";
125 | 	cin>>index;
126 | 	Node *q=NULL;
127 | 	while(ptr->rollNo!=index)
128 | 	{
129 | 		ptr=ptr->next;
130 | 	}
131 | 	temp->next=ptr->next;
132 | 	ptr->next=temp;
133 | 	
134 | }
135 | 
136 | void deleteAnyNode()
137 | {
138 | 	Node *p1 = head;
139 | 	Node *p2=NULL;
140 | 	cout<<"Enter the rollNo which you want to delete : ";
141 | 	int r;
142 | 	cin>>r;
143 | 	if(head->rollNo == r)				// Condition for if deleteing node is first one
144 | 	{
145 | 		Node *p = head;
146 | 		head=head->next;
147 | 	}else						// for all other nodes
148 | 	{
149 | 		while(p1->rollNo != r)
150 | 		{
151 | 			p2=p1;
152 | 			p1=p1->next;
153 | 		}
154 | 		p2->next=p1->next;
155 | 	}
156 | }
157 | 
158 | void dupliRoll()		// REMOVED DUPLICATE ELEMNTS FROM SORTED LINKED LISTS)
159 | {
160 | 	Node *p1 = head;
161 | 	Node *p2 = head->next;
162 | 	
163 | 	while(p1->next!=NULL)
164 | 	{
165 | 		if(p1->rollNo!=p2->rollNo)
166 | 		{
167 | 			p1=p2;
168 | 			p2=p2->next;
169 | 		}else
170 | 		{
171 | 			p1->next=p2->next;
172 | 			p2=p1->next;
173 | 		}	
174 | 	}
175 | }
176 | 
177 | void reverse()
178 | {
179 | 	Node *p = head;
180 | 	Node *q = NULL;
181 | 	Node *r = NULL;
182 | 	
183 | 	while(p!=NULL)
184 | 	{
185 | 		r=q;
186 | 		q=p;
187 | 		p=p->next;
188 | 		q->next=r;
189 | 	}	
190 | 	head = q;
191 | 	
192 | }
193 | int main()
194 | {
195 | 	cout<<"***********************LINKED LIST***************************\n";
196 | 	int ch;
197 | 	do{
198 | 	cout<<"\n1)Insertion\n2)Display\n3)Count Nodes\n4)Search\n5)Make any node as first node\n6)Inserting at any Position\n7)Deleting any node\n8)Remove Duplicate roll numbers\n9)Reverse Linked List\n10)Exit\n";
199 | 	cout<<"Enter your Choice : ";
200 | 	cin>>ch;
201 | 	switch(ch)
202 | 	{
203 | 		case 1 : insert();
204 | 			 break;
205 | 		case 2 : display();
206 | 			 break;
207 | 		case 3 : count();
208 | 			 break;		
209 | 		case 4 : search();
210 | 			 break;		
211 | 		case 5 : makeFirstNode();
212 | 			 break;
213 | 		case 6 : insertAnywhere();
214 | 			 break;
215 | 		case 7 : deleteAnyNode();
216 | 			 break;
217 | 		case 8 : dupliRoll();
218 | 			 break;
219 | 		case 9 : reverse();
220 | 			 break;	
221 | 		case 10 : exit(1);	
222 | 	}while(ch!=10);
223 | 	}
224 | }
225 | 


--------------------------------------------------------------------------------
/Trees/BinarySearchTree.cpp:
--------------------------------------------------------------------------------
  1 | #include<iostream>
  2 | using namespace std;
  3 | 
  4 | struct node
  5 | {
  6 | 	int data;
  7 | 	struct node *right;
  8 | 	struct node *left;
  9 | }*root,*t1,*t2,*t3,*temp, *p;
 10 | 
 11 | class binarytree
 12 | {
 13 | 	public:
 14 | 
 15 | 		node* insert(node*p, int key)
 16 | 		{
 17 | 		    if(p == NULL)
 18 |             {
 19 |                 p = new node;
 20 |                 p->data = key;
 21 |                 p->right = NULL;
 22 |                 p->left = NULL;
 23 | 
 24 |                 return p;
 25 |             }
 26 |             if( key < p->data)
 27 |                 p->left = insert(p->left,key);
 28 | 
 29 | 			else if( key > p->data)
 30 |                 p->right = insert(p->right,key);
 31 | 
 32 |             return p;
 33 | 		}
 34 | 
 35 | 		node* Search(node *p,int key)
 36 | 		{
 37 | 
 38 | 		    while(p != NULL)
 39 | 		    {
 40 | 		       if(key == p->data)
 41 |                     return p;
 42 | 
 43 |                else if(key < p->data)
 44 |                     p = p->left;
 45 | 
 46 |                else if(key > p->data)
 47 |                     p = p->right;
 48 | 		    }
 49 |             return NULL;
 50 | 		}
 51 | 
 52 | 
 53 | 		void preorder(node *t2)
 54 | 		{
 55 | 			if(t2 == NULL)
 56 | 			return;
 57 | 			cout<<t2->data<<" ";
 58 | 			preorder(t2->left);
 59 | 			preorder(t2->right);
 60 | 		}
 61 | 
 62 | 		void inorder(node *t2)
 63 | 		{
 64 | 			if(t2 == NULL)
 65 | 			return;
 66 | 			inorder(t2->left);
 67 | 			cout<<t2->data<<" ";
 68 | 			inorder(t2->right);
 69 | 		}
 70 | 
 71 | 		void postorder(node *t2)
 72 | 		{
 73 | 			if(t2 == NULL)
 74 | 			return;
 75 | 			postorder(t2->left);
 76 | 			postorder(t2->right);
 77 | 			cout<<t2->data<<" ";
 78 | 		}
 79 | 
 80 | 		void leftmost(node *t2)
 81 | 		{
 82 | 			while(t2->left!= NULL)
 83 | 			    t2 = t2->left;
 84 | 			cout<<"\n========================================\n";
 85 | 			cout<<"Smallest number(Leftmost)  is- "<<t2->data<<endl;
 86 | 			cout<<"========================================\n";
 87 | 		}
 88 | 
 89 | 		void rightmost(node *t2)
 90 | 		{
 91 | 			while(t2->right!= NULL)
 92 | 			    t2 = t2->right;
 93 | 			cout<<"\n========================================\n";
 94 | 			cout<<"Biggest number(rightmost)  is- "<<t2->data<<endl;
 95 | 			cout<<"========================================\n";
 96 | 		}
 97 | 
 98 | 		int Height(node *p)
 99 | 		{
100 | 
101 | 		    if(p != NULL)
102 | 		    {
103 | 		       int s1 = Height(p->left);
104 | 		       int s2 = Height(p->right);
105 | 
106 |             if(s1>s2)
107 | 		        return s1 + 1;
108 |             else
109 | 		        return s2 + 1;
110 | 		    }
111 | 
112 |             return 0;
113 | 		}
114 | 
115 | 		int Count(node *p)
116 | 		{
117 | 
118 | 		    if(p != NULL)
119 | 		    {
120 | 		       int x = Count(p->left);
121 | 		       int y = Count(p->right);
122 |                return x+y+1;
123 | 		    }
124 |             return 0;
125 | 		}
126 | 
127 | 		int Countdouble(node *p)
128 | 		{
129 | 
130 | 		    if(p != NULL)
131 | 		    {
132 | 		       int x = Countdouble(p->left);
133 | 		       int y = Countdouble(p->right);
134 | 
135 |                if((p->left != NULL) and (p->right != NULL))
136 |                     return x+y+1;
137 |                else
138 |                     return x+y;
139 | 		    }
140 |             return 0;
141 | 		}
142 | 
143 | 		int Countleaf(node *p)
144 | 		{
145 | 
146 | 		    if(p != NULL)
147 | 		    {
148 | 		       int x = Countleaf(p->left);
149 | 		       int y = Countleaf(p->right);
150 | 
151 |                if((p->left == NULL) and (p->right == NULL))
152 |                     return x+y+1;
153 |                else
154 |                     return x+y;
155 | 		    }
156 |             return 0;
157 | 		}
158 | 
159 | 
160 | 
161 | };
162 | int main()
163 | {
164 |     class binarytree b1;
165 | 	int ch,newdata;
166 | 	root = NULL;
167 | 	cout<<"Enter the value of root node: ";
168 | 	cin>>newdata;
169 | 	root =  b1.insert(root,newdata);
170 | 	while(1)
171 | 	{
172 | 		cout<<"\nPress 1 to insert new element"<<endl;
173 | 		cout<<"Press 2 to search an element"<<endl;
174 | 		cout<<"Press 3 to display preorder travelsal"<<endl;
175 | 		cout<<"Press 4 to display inorder travelsal"<<endl;
176 | 		cout<<"Press 5 to display postorder travelsal"<<endl;
177 | 		cout<<"Press 6 to display Smallest number"<<endl;
178 | 		cout<<"Press 7 to display Largest number"<<endl;
179 | 		cout<<"Press 8 to calculate the height"<<endl;
180 | 		cout<<"Press 9 to calculate number of nodes"<<endl;
181 |         cout<<"Press 10 to exit"<<endl;
182 | 		cout<<"Enter your choice:- ";
183 | 		cin>>ch;
184 | 		switch(ch)
185 | 		{
186 | 			case 1: cout<<"\nEnter the value of the element to be inserted:- ";
187 | 					cin>>newdata;
188 | 					b1.insert(root,newdata);
189 | 					cout<<"\n=======element entered successfully========\n";
190 | 					break;
191 | 			case 2: cout<<"\nEnter the value of the element to be searched:- ";
192 | 					cin>>newdata;
193 |                         temp = b1.Search(root,newdata);
194 |                         if(temp != NULL)
195 |                             cout<<"Found!\n";
196 |                         else
197 |                             cout<<"Not Found!\n";
198 | 					break;
199 | 			case 3: cout<<"\n========================================\n";
200 |                     cout<<"Preoder travelsal:- ";
201 | 					b1.preorder(root);
202 | 					cout<<"\n========================================\n";
203 | 					break;
204 | 			case 4: cout<<"\n========================================\n";
205 |                     cout<<"Inoder travelsal:- ";
206 | 					b1.inorder(root);
207 | 					cout<<"\n========================================\n";
208 | 					break;
209 | 			case 5:	cout<<"\n========================================\n";
210 |                     cout<<"Postoder travelsal:- ";
211 | 					b1.postorder(root);
212 | 					cout<<"\n========================================\n";
213 | 					break;
214 | 			case 6:	b1.leftmost(root);
215 | 					break;
216 | 			case 7:	b1.rightmost(root);
217 | 					break;
218 | 			case 8:	cout<<"\n========================================\n";
219 |                     cout<<"Height of tree is: "<<b1.Height(root);
220 | 					cout<<"\n========================================\n";
221 | 					break;
222 | 			case 9:	cout<<"\n========================================\n";
223 |                     cout<<"Total number of nodes are: "<<b1.Count(root);
224 |                     cout<<"\nTotal number of leaf nodes are: "<<b1.Countleaf(root);
225 |                     cout<<"\nTotal number of 2 degree nodes are: "<<b1.Countdouble(root);
226 | 					cout<<"\n========================================\n";
227 | 					break;
228 | 			case 10: return 0;
229 | 
230 | 			default: cout<<"Enter a valid input\n";
231 | 		}
232 | 	}
233 | 	return 0;
234 | }
235 | 


--------------------------------------------------------------------------------
/Trees/AVL-Tree.cpp:
--------------------------------------------------------------------------------
  1 | #include<iostream>
  2 | using namespace std;
  3 | 
  4 | struct node
  5 | {
  6 | 	int data;
  7 | 	int height;
  8 | 	struct node *right;
  9 | 	struct node *left;
 10 | }*root,*t1,*t2,*t3,*temp, *p;
 11 | 
 12 | class AVL
 13 | {
 14 | 	public:
 15 | 
 16 | 		node* insert(node*p, int key)
 17 | 		{
 18 | 		    if(p == NULL)
 19 |             {
 20 |                 p = new node;
 21 |                 p->data = key;
 22 |                 p->height = 1;
 23 |                 p->right = NULL;
 24 |                 p->left = NULL;
 25 | 
 26 |                 return p;
 27 |             }
 28 |             if( key < p->data)
 29 |                 p->left = insert(p->left,key);
 30 | 
 31 | 			else if( key > p->data)
 32 |                 p->right = insert(p->right,key);
 33 | 
 34 |         /***********UPDATE THE HEIGHT**********/
 35 | 
 36 |             p->height = NodeHeight(p);
 37 | 
 38 |         /**********CHECK FOR BALANCE FACTOR FOR ROTATIONS*********/
 39 | 
 40 |         /***See if Balance factor is +ve than we have to check left side else if -ve we have to check right side***/
 41 | 
 42 |         if((BalanceFactor(p) == 2) and (BalanceFactor(p->left) == 1))
 43 |             return LLrotation(p);
 44 |         else if((BalanceFactor(p) == 2) and (BalanceFactor(p->left) == -1))
 45 |             return LRrotation(p);
 46 |         else if((BalanceFactor(p) == -2) and (BalanceFactor(p->right) == 1))
 47 |             return RLrotation(p);
 48 |         else if((BalanceFactor(p) == -2) and (BalanceFactor(p->right) == -1))
 49 |             return RRrotation(p);
 50 | 
 51 | 
 52 |             return p;
 53 | 		}
 54 | 
 55 | 		int NodeHeight(node *t1)
 56 | 		{
 57 |             int hl = t1 && t1->left ? t1 -> left -> height : 0;
 58 |             int hr = t1 && t1->right ? t1 -> right -> height : 0;
 59 | 
 60 |             if(hl > hr)
 61 |                 return hl + 1;
 62 |             else
 63 |                 return hr + 1;
 64 | 		}
 65 | 
 66 | 		int BalanceFactor(node *t1)
 67 | 		{
 68 |             int hl = t1 && t1->left ? t1 -> left -> height : 0;
 69 |             int hr = t1 && t1->right ? t1 -> right -> height : 0;
 70 | 
 71 |             return hl - hr;
 72 | 		}
 73 | 
 74 | 		node* LLrotation(node *t)
 75 | 		{
 76 |             node *tl = t->left;
 77 |             node *tlr = tl->right;
 78 | 
 79 |             tl->right = t;
 80 |             t->left = tlr;
 81 | 
 82 |             t->height = NodeHeight(t);
 83 |             tl->height = NodeHeight(tl);
 84 | 
 85 |             if(t == root)
 86 |                 root = tl;
 87 | 
 88 |             return tl;
 89 | 		}
 90 | 
 91 | 		node* LRrotation(node *t)
 92 |         {
 93 |             node *tl = t->left;
 94 |             node *tlr = tl->right;
 95 | 
 96 |             tl->right = tlr->left;
 97 |             t->left = tlr->right;
 98 | 
 99 | 
100 |             tlr->left = tl;
101 |             tlr->right = t;
102 | 
103 |             tl->height=NodeHeight(tl);
104 |             t->height=NodeHeight(t);
105 |             tlr->height=NodeHeight(tlr);
106 | 
107 |             if(root==t)
108 |                 root=tlr;
109 |             return tlr;
110 |         }
111 | 
112 |         node* RRrotation(node *t)
113 | 		{
114 |             node *tr = t->right;
115 |             node *trl = tr->left;
116 | 
117 |             tr->left = t;
118 |             t->right = trl;
119 | 
120 |             t->height = NodeHeight(t);
121 |             tr->height = NodeHeight(tr);
122 | 
123 |             if(t == root)
124 |                 root = tr;
125 | 
126 |             return tr;
127 | 		}
128 | 
129 |         node* RLrotation(node *t)
130 |         {
131 |             node *tr = t->right;
132 |             node *trl = tr->left;
133 | 
134 |             tr->left = trl->right;
135 |             t->right = trl->left;
136 | 
137 | 
138 |             trl->left = t;
139 |             trl->right = tr;
140 | 
141 |             tr->height=NodeHeight(tr);
142 |             t->height=NodeHeight(t);
143 |             trl->height=NodeHeight(trl);
144 | 
145 |             if(root==t)
146 |                 root=trl;
147 |             return trl;
148 |         }
149 | 
150 | 		node* Search(node *p,int key)
151 | 		{
152 | 
153 | 		    while(p != NULL)
154 | 		    {
155 | 		       if(key == p->data)
156 |                     return p;
157 | 
158 |                else if(key < p->data)
159 |                     p = p->left;
160 | 
161 |                else if(key > p->data)
162 |                     p = p->right;
163 | 		    }
164 |             return NULL;
165 | 		}
166 | 
167 | 
168 | 		void preorder(node *t2)
169 | 		{
170 | 			if(t2 == NULL)
171 | 			return;
172 | 			cout<<t2->data<<" ";
173 | 			preorder(t2->left);
174 | 			preorder(t2->right);
175 | 		}
176 | 
177 | 		void inorder(node *t2)
178 | 		{
179 | 			if(t2 == NULL)
180 | 			return;
181 | 			inorder(t2->left);
182 | 			cout<<t2->data<<" ";
183 | 			inorder(t2->right);
184 | 		}
185 | 
186 | 		void postorder(node *t2)
187 | 		{
188 | 			if(t2 == NULL)
189 | 			return;
190 | 			postorder(t2->left);
191 | 			postorder(t2->right);
192 | 			cout<<t2->data<<" ";
193 | 		}
194 | 
195 | 		void leftmost(node *t2)
196 | 		{
197 | 			while(t2->left!= NULL)
198 | 			    t2 = t2->left;
199 | 			cout<<"\n========================================\n";
200 | 			cout<<"Smallest number(Leftmost)  is- "<<t2->data<<endl;
201 | 			cout<<"========================================\n";
202 | 		}
203 | 
204 | 		void rightmost(node *t2)
205 | 		{
206 | 			while(t2->right!= NULL)
207 | 			    t2 = t2->right;
208 | 			cout<<"\n========================================\n";
209 | 			cout<<"Biggest number(rightmost)  is- "<<t2->data<<endl;
210 | 			cout<<"========================================\n";
211 | 		}
212 | 
213 | 		int Height(node *p)
214 | 		{
215 | 
216 | 		    if(p != NULL)
217 | 		    {
218 | 		       int s1 = Height(p->left);
219 | 		       int s2 = Height(p->right);
220 | 
221 |             if(s1>s2)
222 | 		        return s1 + 1;
223 |             else
224 | 		        return s2 + 1;
225 | 		    }
226 | 
227 |             return 0;
228 | 		}
229 | 
230 | 		int Count(node *p)
231 | 		{
232 | 
233 | 		    if(p != NULL)
234 | 		    {
235 | 		       int x = Count(p->left);
236 | 		       int y = Count(p->right);
237 |                return x+y+1;
238 | 		    }
239 |             return 0;
240 | 		}
241 | 
242 | 		int Countdouble(node *p)
243 | 		{
244 | 
245 | 		    if(p != NULL)
246 | 		    {
247 | 		       int x = Countdouble(p->left);
248 | 		       int y = Countdouble(p->right);
249 | 
250 |                if((p->left != NULL) and (p->right != NULL))
251 |                     return x+y+1;
252 |                else
253 |                     return x+y;
254 | 		    }
255 |             return 0;
256 | 		}
257 | 
258 | 		int Countleaf(node *p)
259 | 		{
260 | 
261 | 		    if(p != NULL)
262 | 		    {
263 | 		       int x = Countleaf(p->left);
264 | 		       int y = Countleaf(p->right);
265 | 
266 |                if((p->left == NULL) and (p->right == NULL))
267 |                     return x+y+1;
268 |                else
269 |                     return x+y;
270 | 		    }
271 |             return 0;
272 | 		}
273 | 
274 | 
275 | 
276 | };
277 | int main()
278 | {
279 |     class AVL b1;
280 | 	int ch,newdata;
281 | 	root = NULL;
282 | 	cout<<"Enter the value of root node: ";
283 | 	cin>>newdata;
284 | 	root =  b1.insert(root,newdata);
285 | 	while(1)
286 | 	{
287 | 		cout<<"\nPress 1 to insert new element"<<endl;
288 | 		cout<<"Press 2 to search an element"<<endl;
289 | 		cout<<"Press 3 to display preorder travelsal"<<endl;
290 | 		cout<<"Press 4 to display inorder travelsal"<<endl;
291 | 		cout<<"Press 5 to display postorder travelsal"<<endl;
292 | 		cout<<"Press 6 to display Smallest number"<<endl;
293 | 		cout<<"Press 7 to display Largest number"<<endl;
294 | 		cout<<"Press 8 to calculate the height"<<endl;
295 | 		cout<<"Press 9 to calculate number of nodes"<<endl;
296 |         cout<<"Press 10 to exit"<<endl;
297 | 		cout<<"Enter your choice:- ";
298 | 		cin>>ch;
299 | 		switch(ch)
300 | 		{
301 | 			case 1: cout<<"\nEnter the value of the element to be inserted:- ";
302 | 					cin>>newdata;
303 | 					b1.insert(root,newdata);
304 | 					cout<<"\n=======element entered successfully========\n";
305 | 					break;
306 | 			case 2: cout<<"\nEnter the value of the element to be searched:- ";
307 | 					cin>>newdata;
308 |                         temp = b1.Search(root,newdata);
309 |                         if(temp != NULL)
310 |                             cout<<"Found!\n";
311 |                         else
312 |                             cout<<"Not Found!\n";
313 | 					break;
314 | 			case 3: cout<<"\n========================================\n";
315 |                     cout<<"Preoder travelsal:- ";
316 | 					b1.preorder(root);
317 | 					cout<<"\n========================================\n";
318 | 					break;
319 | 			case 4: cout<<"\n========================================\n";
320 |                     cout<<"Inoder travelsal:- ";
321 | 					b1.inorder(root);
322 | 					cout<<"\n========================================\n";
323 | 					break;
324 | 			case 5:	cout<<"\n========================================\n";
325 |                     cout<<"Postoder travelsal:- ";
326 | 					b1.postorder(root);
327 | 					cout<<"\n========================================\n";
328 | 					break;
329 | 			case 6:	b1.leftmost(root);
330 | 					break;
331 | 			case 7:	b1.rightmost(root);
332 | 					break;
333 | 			case 8:	cout<<"\n========================================\n";
334 |                     cout<<"Height of tree is: "<<b1.Height(root);
335 | 					cout<<"\n========================================\n";
336 | 					break;
337 | 			case 9:	cout<<"\n========================================\n";
338 |                     cout<<"Total number of nodes are: "<<b1.Count(root);
339 |                     cout<<"\nTotal number of leaf nodes are: "<<b1.Countleaf(root);
340 |                     cout<<"\nTotal number of 2 degree nodes are: "<<b1.Countdouble(root);
341 | 					cout<<"\n========================================\n";
342 | 					break;
343 | 			case 10: return 0;
344 | 
345 | 			default: cout<<"Enter a valid input\n";
346 | 		}
347 | 	}
348 | 	return 0;
349 | }
350 | 


--------------------------------------------------------------------------------