普通快速排序的两种实现

#include<iostream>
using namespace std;

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

void dump(int arr[],int cnt)
{
    for(int i=0;i<cnt;i++){
        cout<<arr[i]<<" ";
    }
    cout<<endl;
}


void QSort(int arr[],int start,int end)
{
    if(start>=end)return;
    int i=start,j=end;
    int key = arr[i];
    while(i<j)
    {
        while(i<j && arr[j] > key)j--;
        arr[i] = arr[j];
        while(i<j && arr[i] <= key)i++;
        arr[j] = arr[i];
    }
    arr[i] = key;
    QSort(arr,start,i-1);
    QSort(arr,i+1,end);
}

void QSort1(int arr[],int start,int end)
{
    int tmp;
    if(start>=end)return;
    int key=arr[end];
    int i = start;
    for(int j=start;j<end;j++){
        if(arr[j]>=key){
            tmp=arr[j];
            arr[j]=arr[i];
            arr[i]=tmp;
            i++;
        }
    }
    arr[end]=arr[i];
    arr[i]=key;
    QSort1(arr,start,i-1);
    QSort1(arr,i+1,end);
}

int main()
{
    QSort(arr,0,9);
    dump(arr,10);
    QSort1(arr,0,9);
    dump(arr,10);
    return 0;
}