C++ 快速排序

[cpp]
int partion(int a[],int low,int high) 
{ 
    int key=a[low]; 
    while(low<high) 
    { 
        while (low<high&&key<a[high]) 
            high--; 
        if(low<high) 
        { 
            a[low]=a[high]; 
            a[high]=key; 
        } 
        while (low<high&&key>a[low]) 
            low++; 
        if(low<high) 
        { 
            a[high]=a[low]; 
            a[low]=key; 
        } 
    } 
    return low; 
} 
void quick_sort(int a[],int low,int high) 
{ 
    if(low<high) 
    { 
        int mid=partion(a,low,high); 
        quick_sort(a,0,mid-1); 
        quick_sort(a,mid+1,high); 
    } 
}