快速排序

作者 ： 卿笃军

#include <stdio.h>void Qsort(int a[], int low, int high){int Select = a[low];          int i = low, j = high;    //确保low,high值不变if (i >= j)return;else{while (i < j)          //i < j 确保两个寻找下标不冲突{while (a[j] > Select && i < j)  //从右往左找比Select小的值--j;a[i] = a[j];                    //将该值放在上一步空出的位置while (a[i] <= Select && i < j) //从左往右找比Select大的值++i;a[j] = a[i];                    //将该值放在上一步空出的位置}}a[i] = Select;   //或者a[j] = Select; 此时i == j，将该数放入，此时Select已经排放好Qsort(a, low, i-1);   //先排左边，i-1和j-1是一样的Qsort(a, i+1, high);  //排右边}int main(){int i, a[5] = {13,4,7,8,2};Qsort(a, 0, 4);for (i = 0; i < 5; ++i)printf("%d ",a[i]);return 0;}