#include <stdio.h>
int a[10]={6,2,8,10,5,1,7,3,4,9};

int partition(int l, int u) {
  int p=a[l], i=l-1, j=u+1,t;

  while (1) {
    do  i++;  while (a[i] < p);
    do  j--;  while (a[j] > p);

    if (i < j) { t=a[i]; a[i]=a[j]; a[j]=t; }
    else  return j;
  }
}

void quicksort(int l, int u) {
  int pivot;

  if (l < u) {
    pivot=partition(l,u);
    quicksort(l,pivot-1);
    quicksort(pivot+1,u);
  }
}

void main() {
 int i,j;

 clrscr();
 printf("original order --> \n");
 for (i=0; i<10; i++) printf("%2d ",a[i]); printf("\n");

 quicksort(0,9);
 printf("sorted order --> \n");
 for (i=0; i<10; i++) printf("%2d ",a[i]); printf("\n");
}