/*
 * Quicksort implementation example
 */

#include <stdio.h>
 
#define MAXSIZE 8

void quicksort(int x[], int first, int last){
    int pivot, i, j, s;

    if (first < last){
        pivot = first;
        i = first;
        j = last;

        /* Sort in ascending order */
        while(i < j){
            while((x[i] <= x[pivot]) && (i < last) )
                i++;
            while(x[j] > x[pivot])
                j--;
            if(i < j){
                s = x[i];
                x[i] = x[j];
                x[j] = s;
            }
        }

        s = x[pivot];
        x[pivot] = x[j];
        x[j] = s;

        quicksort(x, first, j-1);
        quicksort(x, j+1, last);

    }
}

void bubble_sort(int n, int list[]) {
    int i, j, s;
 
    for (i = 0 ; i < n - 1; i++) {
        for (j = 0 ; j < n - i - 1; j++) {
            /* Sort in ascending order */
            if (list[j] > list[j+1]) {
                /* swap */
                s = list[j];
                list[j] = list[j+1];
                list[j+1] = s;
            }
        }
    }
}

int main(void) {
    int a[MAXSIZE], n = MAXSIZE, i;
 
    /*
     * Worst case scenario - a list in descending order
     */
    printf("Original list in descending order:\n");
    for (i = 0 ; i < n ; i++) {
        a[i] = n - i;
        printf("%3d\n", a[i]);
    }
 
    /*bubble_sort(n, a);*/
    quicksort(a, 0, n-1);
 
    printf("Sorted list in ascending order:\n");
 
    for (i = 0 ; i < n ; i++) {
        printf("%3d\n", a[i]);
    }
 
  return 0;
}