82 lines
1.8 KiB
C
82 lines
1.8 KiB
C
// gcc qs.c -o qs && ./qs
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// Quick sort in C
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#include <stdio.h>
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// function to swap elements
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void swap(int *a, int *b) {
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int t = *a;
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*a = *b;
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*b = t;
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}
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// function to find the partition position
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int partition(int array[], int low, int high) {
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// select the rightmost element as pivot
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int pivot = array[high];
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// pointer for greater element
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int i = (low - 1);
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// traverse each element of the array
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// compare them with the pivot
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for (int j = low; j < high; j++) {
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if (array[j] <= pivot) {
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// if element smaller than pivot is found
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// swap it with the greater element pointed by i
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i++;
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// swap element at i with element at j
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swap(&array[i], &array[j]);
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}
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}
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// swap the pivot element with the greater element at i
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swap(&array[i + 1], &array[high]);
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// return the partition point
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return (i + 1);
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}
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void quickSort(int array[], int low, int high) {
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if (low < high) {
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// find the pivot element such that
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// elements smaller than pivot are on left of pivot
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// elements greater than pivot are on right of pivot
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int pi = partition(array, low, high);
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// recursive call on the left of pivot
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quickSort(array, low, pi - 1);
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// recursive call on the right of pivot
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quickSort(array, pi + 1, high);
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}
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}
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// function to print array elements
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void printArray(int array[], int size) {
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for (int i = 0; i < size; ++i) {
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printf("%d ", array[i]);
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}
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printf("\n");
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}
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// main function
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int main() {
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int data[] = {8, 7, 2, 1, 0, 9, 6};
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int n = sizeof(data) / sizeof(data[0]);
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printf("Unsorted Array\n");
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printArray(data, n);
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// perform quicksort on data
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quickSort(data, 0, n - 1);
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printf("Sorted array in ascending order: \n");
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printArray(data, n);
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}
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