快速排序

问题：找临界点挺难的，是了好几次，终于OK了。

代码：

#include <iostream>
 
using namespace std;
 
void qSort(int arr[],int left,int right)
{
    int i,j;
    int pos;
    static int count=1;
    if(left>=right)
        return;
     
    i=left;
    j=right;
    int key=arr[i];
    pos=i;
    while(i<j)
    {
        while(i<j&&arr[j]>=key)
        {
            j--;
        }
        if(i<j&&arr[j]<key)
        {
            arr[pos]=arr[j];
            arr[j]=key; 
            pos=j;
            j--;
        }
        while(i<=j&&arr[i]<=key)
        {
            i++;
        }
        if(i<=j&&arr[i]>key)
        {
           arr[pos]=arr[i];
           arr[i]=key;
           pos=i;
           i++;
        }
 
    }
    cout<<"第"<<count<<"次快速排序-"<<j<<":";
    for(int k=left;k<=right;k++)
        cout<<arr[k]<<"  ";
    cout<<endl;
    count++;
    qSort(arr,left,j);
    qSort(arr,j+1,right);
 
     
     
}
 
int main()
{
    int arr[]={8,7,6,5,4,3,2,1};
    cout<<"快速排序前:"<<endl;
    for(int i=0;i<8;i++)
    {
        cout<<arr[i]<<"  ";
    }
    cout<<endl<<endl;
    qSort(arr,0,7);
    cout<<endl;
    cout<<"快速排序后:"<<endl;
    for(int j=0;j<8;j++)
    {
        cout<<arr[j]<<"  ";
    }
    cout<<endl;
    return 0;
}