排序：快速排序

#include<iostream>using namespace std;int pnumsrtition(int nums[], int low, int high){    int pivot_key = nums[low];//用區間的第1個記錄作為基準    while (low < high){//從區間兩端交替向中間掃描，直到low=high為止        while (low < high&&nums[high] >= pivot_key)            high--;//從右向左掃描，查到第1個關鍵字小於pivot_key的記錄nums[hgih]        if (low < high)            nums[low++] = nums[high];//相當於交換nums[low]和nums[high]        while (low < high&&nums[low] <= pivot_key)            low++;        if (low < high)            nums[high--] = nums[low];    }    nums[low] = pivot_key;//基準記錄已被最後定位    return low;}void quick_sort(int nums[], int low, int high){    int pivot; //劃分後的基準記錄的位置    if (low < high){        pivot = pnumsrtition(nums, low, high);//做劃分        quick_sort(nums, low, pivot - 1);        quick_sort(nums, pivot + 1, high);    }}void print_numsrrnumsy(int nums[], int len){    for (int i = 0; i < len; i++)        cout << nums[i] << ' ';    cout << endl;}int main(){    int nums[] = { 9, 1, 5, 8, 3, 7, 4, 6, 2 };    int len = sizeof(nums) / sizeof(int);    quick_sort(nums, 0, len - 1);    print_numsrrnumsy(nums, len);    return 0;}