> void Qsort(int low, int high)
> {
> 	if (low >= high)
> 	{
> 		return ;
> 	}
> 	int l, mid, r, pivot;
>     //mid = low +(high-low)>>1; // + -的优先级比>>还大,又一次在这里翻船了!!!!
> 	mid = low + (high-low>>1); 
> 	Swap(arr[mid], arr[high]);
> 
> 	l = low, r = high-1;
> 	while (l<=r)
> 	{
> 		while (l<=r && arr[l] <= arr[high])
> 		{
> 			l++;
> 		}
> 		while (l<=r && arr[r] >= arr[high])
> 		{
> 			r--;
> 		}
> 
> 		if (l<=r)
> 		{
> 			Swap(arr[l], arr[r]);
> 			l++;
> 			r--;
> 		}
> 
> 		if (l>r)
> 		{
> 			pivot = l;
> 			break;
> 		}
> 	}
> 
> 	Swap(arr[pivot], arr[high]);
> 	Qsort(low, pivot-1);
> 	Qsort(pivot+1, high);
> 
> 
> }