快速排序

#include<stdio.h>

void swap(int a[],int low,int high) {
    int temp;

    temp = a[low];
    a[low] = a[high];
    a[high] = temp;
}
int Partition(int a[],int low,int high) {

    int point;

    // 优化point的初始值
    int m = low + (high - low) /2;

    if (a[low]>a[high]) {
        swap(a,low,high);
    }
    if (a[m]>a[high]){
        swap(a,m,high);
    }
    if(a[m]>a[low]){
        swap(a,m,low);
    }
    point = a[low];

    while(low<high) {
        while(low<high&&a[high] >= point){
            high--;
        }
        // 优化交换
        a[low] = a[high];
        while(low<high&&a[low] <= point){
            low++;
        }
        a[high] = a[low];
    }
    a[low] = point;

    return low;
}

void QSort(int a[],int low, int high) {
    int point;

    if( low < high ){
        point = Partition(a,low,high);
        QSort(a,low,point-1);
        QSort(a,point+1,high);
    }
}

void QuickSort(int a[], int n) {
    QSort(a,0,n-1);
}

int main() {

    int i;

    int a[10] = {9,8,7,6,5,4,3,2,1,0};

    printf("排序后:");

    QuickSort(a,10);

    for( i=0; i<10; i++) {
        printf("%d ",a[i]);
    }

    printf("\n");
}