└── Quick sort


/Quick sort:
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 1 | // Quick sort in C
 2 | 
 3 | #include <stdio.h>
 4 | 
 5 | // function to swap elements
 6 | void swap(int *a, int *b) {
 7 |   int t = *a;
 8 |   *a = *b;
 9 |   *b = t;
10 | }
11 | 
12 | // function to find the partition position
13 | int partition(int array[], int low, int high) {
14 |   
15 |   // select the rightmost element as pivot
16 |   int pivot = array[high];
17 |   
18 |   // pointer for greater element
19 |   int i = (low - 1);
20 | 
21 |   // traverse each element of the array
22 |   // compare them with the pivot
23 |   for (int j = low; j < high; j++) {
24 |     if (array[j] <= pivot) {
25 |         
26 |       // if element smaller than pivot is found
27 |       // swap it with the greater element pointed by i
28 |       i++;
29 |       
30 |       // swap element at i with element at j
31 |       swap(&array[i], &array[j]);
32 |     }
33 |   }
34 | 
35 |   // swap the pivot element with the greater element at i
36 |   swap(&array[i + 1], &array[high]);
37 |   
38 |   // return the partition point
39 |   return (i + 1);
40 | }
41 | 
42 | void quickSort(int array[], int low, int high) {
43 |   if (low < high) {
44 |     
45 |     // find the pivot element such that
46 |     // elements smaller than pivot are on left of pivot
47 |     // elements greater than pivot are on right of pivot
48 |     int pi = partition(array, low, high);
49 |     
50 |     // recursive call on the left of pivot
51 |     quickSort(array, low, pi - 1);
52 |     
53 |     // recursive call on the right of pivot
54 |     quickSort(array, pi + 1, high);
55 |   }
56 | }
57 | 
58 | // function to print array elements
59 | void printArray(int array[], int size) {
60 |   for (int i = 0; i < size; ++i) {
61 |     printf("%d  ", array[i]);
62 |   }
63 |   printf("\n");
64 | }
65 | 
66 | // main function
67 | int main() {
68 |   int data[] = {8, 7, 2, 1, 0, 9, 6};
69 |   
70 |   int n = sizeof(data) / sizeof(data[0]);
71 |   
72 |   printf("Unsorted Array\n");
73 |   printArray(data, n);
74 |   
75 |   // perform quicksort on data
76 |   quickSort(data, 0, n - 1);
77 |   
78 |   printf("Sorted array in ascending order: \n");
79 |   printArray(data, n);
80 | }
81 | 


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