快速排序

#include<stdio.h>

typedef struct NODE
{
    int data;
    struct NODE *next;
}Node;

#define N 10

int partition(int a[], int left, int right)
{
    int low, high;
    int pivot = a[left];

    low = left;
    high = right;

    while(low < high)
    {
        while(low < high && a[high] > pivot)
        {
            high--;
        }
        //high从右向左找小于pivot 的元素
        if(low < high)
        {
            a[low++] = a[high];
        }


        while(low < high && a[low] < pivot)
        {
            low++;
        }
        //low 从左向右找大于pivot 的元素
        if(low < high)
        {
            a[high--] = a[low];
        }                
    }

    a[low] = pivot;//将枢轴元素保存到low=high的位置
        
    return low; //返回枢轴元素的位置
    
}

int QuickSort(int a[], int low, int high)
{
    int p;

    if(low < high)
    {
        p = partition(a, low, high);
        QuickSort(a, low, p - 1);
        QuickSort(a, p + 1, high);
    }

    return 0;
}


//测试程序
void main()
{
    int a[N] = {2, 5, 3,  8, 10, 0, -5,  4, 34, 11};
    int m, n;
    int ret = 0;
    int i;

    m = 0;
    n = N -1;

    printf("before:");
    for(i = 0; i < N; i++)
    {
        printf("%d ", a[i]);
    }
    printf("\nafter:");
    
    ret = QuickSort(a, m, n);
    
    for(i = 0; i < N; i++)
    {
        printf("%d ", a[i]);
    }
    printf("\nret:%d\n", ret);
    
}