qsort.c

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

#define N 10

int sort[N];

void quickSort(int bottom, int top, int *data)
{
    int lower, upper, div, temp;
    if ( bottom >= top )
        return;

    div = data[bottom];

    for ( lower = bottom, upper = top; lower < upper; ) {
        while ( lower <= upper && data[lower] <= div ) {
            lower++;
        }
        while ( lower <= upper && data[upper] > div ) {
            upper--;
        }
        if ( lower < upper ) {
            temp = data[lower];
            data[lower] = data[upper];
            data[upper] = temp;
        }
    }

    temp = data[bottom];
    data[bottom] = data[upper];
    data[upper]  = temp;

    quickSort(bottom, upper - 1, data);
    quickSort(upper + 1, top, data);
}

int main(void)
{
    int i;

    srand((unsigned int) time(NULL));

    for ( i = 0; i < N; i++ ) {
        sort[i] = rand();
        printf("%010d ", sort[i]);
    }

    printf("\n\nstart...\n\n");
    quickSort(0, N - 1, sort);

    for ( i = 0; i < N; i++ ) {
        printf("%010d ", sort[i]);
    }

    return 0;
}