快速排序（quick sort）C++实现

#include <iostream>
#include <vector>
#include <unistd.h>
using namespace std;

int quickSort(vector<int> &arr,int l,int r)
{
    int len = r+1;
    int povit = arr[l];
    int index = l;
    l++;
    while(l<=r)
    {
        while(l<len&&arr[l]<=povit) l++;
        while(r>index&&arr[r]>=povit) r--;
       // cout<<"l = "<<l<<" r = "<<r<<endl;
        if(l<len&&r>0&&r>l)
        {
            int temp = arr[l];
            arr[l] = arr[r];
            arr[r] = temp;
        }
    }

    arr[index] = arr[r];
    arr[r] = povit;

    return r;

}
void recrusion(vector<int> &arr,int l,int r)
{
    //cout<<"new rec l = "<<l<<" r = "<<r<<endl;

    if(l>=r) return;
    int index = quickSort(arr,l,r);
    recrusion(arr,l,index-1);
    recrusion(arr,index+1,r);
    return;
}


int main()
{
    int a[] = {38,17,50,77,40,205,5};
    vector<int> arr(a,a+7);

    recrusion(arr,0,arr.size()-1);
    for(int i=0;i<arr.size();i++)
    {
        cout<<arr[i]<<" ";
    }
    cout<<endl;


}