source: Deliverables/D4.1/GCC/QuickSort.c @ 185

#include "stdio.h"

void swap(int *a, int *b)
{
  int t=*a; *a=*b; *b=t;
}
void sort(int arr[], int beg, int end)
{
  if (end > beg + 1)
  {
    int piv = arr[beg], l = beg + 1, r = end;
    while (l < r)
    {
      if (arr[l] <= piv)
        l++;
      else
        swap(&arr[l], &arr[--r]);
    }
    swap(&arr[--l], &arr[beg]);
    sort(arr, beg, l);
    sort(arr, r, end);
  }
}

int main()
{
  int array[3] = { 3, 2, 1 };
  sort(array, 0, 2);
  if(array[0] == 1)
    printf("Yes");
  else
    printf("No"); // Surprise: no should be printed!
}