quicksort.c

#include<stdio.h>

void swap(int* a, int* b)
{
  int t = *a;
  *a = *b;
  *b = t;
}

int partition (int arr[], int low, int high)
{
  int pivot = arr[high];
  int i = (low - 1);

  for (int j = low; j <= high- 1; j++)
  {
    if (arr[j] <= pivot)
    {
      i++;
      swap(&arr[i], &arr[j]);
    }
  }
  swap(&arr[i + 1], &arr[high]);
  return (i + 1);
}

void quickSort(int arr[], int low, int high)
{
  if (low < high)
  {
    int pi = partition(arr, low, high);
    quickSort(arr, low, pi - 1);
    quickSort(arr, pi + 1, high);
  }
}

int main()
{
  int arr[50], i, n;
  printf("Enter no of elements: ");
  scanf("%d", &n);
  for(i=0;i<n;i++)
    scanf("%d", &arr[i]);
  quickSort(arr, 0, n-1);
  printf("Sorted array: ");
  for (i=0; i < n; i++)
      printf("%d ", arr[i]);
  return 0;
}