quickSort（优化）

推荐慕课网，刘宇波老师《算法与数据结构》链接：http://coding.imooc.com/class/71.htmlquickSort（优化） 课堂笔记/*  */#include <cstdlib>#include <iostream>using namespace std;template<typename T>void _quickSort3(T arr[],int l,int r){    swap(arr[l],arr[rand()%(r-l+1)+l]);    T v = arr[l];    int lt = l;    int gt = r+1;    int i = l+1;    while(i < gt){        if(arr[i] < v){            swap(arr[i],arr[lt+1]);            i++,lt++;        }        else if(arr[i] > v){            swap(arr[i],arr[gt-1]);            gt--;        }        else             i++;    }    swap(arr[l],arr[lt]);    _quickSort3(arr,l,lt-1);    _quickSort3(arr,gt,r);}template<typename T>void quickSort3(T arr[],int n){    //srand(time(NULL));    _quickSort3(arr,0,n-1);}int main(){    int a[] = {9,8,7,6,5,4,3,2,1};    int n1 = sizeof(a)/sizeof(a[0]);    quickSort3(a,n1);    for(int i = 0;i < n1;i++)       cout<<a[i]<<" ";    cout<<endl;    return 0;}