快速排序quicksort实现方法

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

#define ARRAY_SIZE 10

void swap(int *x, int *y)
{
    int a = *x;
    *x = *y;
    *y = a;
}

int randint(int low, int high)
{
    return (low + (rand() % (high - low + 1)));
}

void quicksort(int *arr, int low, int high)
{ 
    int i, mid;
    if (low >= high) 
        return;
    swap(arr+low, arr + randint(low, high));
    mid = low;
    for (i = low+1; i <= high; i++)
    {
        if (arr[i] < arr[low])
        {
            swap(arr + ++mid, arr + i);
        }
    }
    swap(arr + low, arr + mid);
    quicksort(arr, low, mid-1);
    quicksort(arr, mid+1, high);
}

void printArray(int *arr, int size, const char *prefix)
{
    printf("%s:", prefix);
    for(int i = 0; i < size - 1; i++)
    {
        printf("%d ", arr[i]);
    }
    printf("
");
}

int main(int argc, char **argv)
{
    int array_unsort[ARRAY_SIZE] = {11, 23, 44, 55, 32, 12, 8, 9, 63, 82};
    printArray(array_unsort, ARRAY_SIZE, "before sort");
    quicksort(array_unsort, 0, ARRAY_SIZE-1);
    printArray(array_unsort, ARRAY_SIZE, "after sort");
    return 0;

}