快速排序的递归和非递归的实现

struct QuickS{
int low;
int high;
};

int Partition(int *arr,int st,int ed){//快速排序的划分
int pos = arr[st];
while(st < ed){
while(arr[ed] > pos && st < ed) ed --;
arr[st] = arr[ed];
while(arr[st] <= pos && st < ed) st ++;
arr[ed] = arr[st];
}
arr[st] = pos;
return st;
}

void QuickSort(int *arr,int st,int ed){//快速排序的递归算法
if(st < ed){
int pos = Partition(arr,st,ed);
QuickSort(arr,st,pos-1);
QuickSort(arr,pos+1,ed);
}

}

void QuickSortN(int *arr,int low,int high){//快速排序的非递归算法
stack<QuickS> S;
QuickS p,q;
p.low = low;p.high = high;S.push(p);
while(!S.empty()){
q = S.top();
S.pop();
if(q.low < q.high){
int pos = Partition(arr,q.low,q.high);
p.low = q.low;p.high = pos - 1;S.push(p);
p.low = pos + 1;p.high = q.high;S.push(p);
}
}
}