归并排序c++实现

void mergeSort(vector<int>& arr, int low, int high){
	if(low >= high)
		return;
	int mid = (low + high) / 2;
	mergeSort(arr, low, mid);
	mergeSort(arr, mid + 1, high);
	vector<int>vec(arr.size());
	int s = 0;
	int i = low;
	int j = mid + 1;
	while(i <= mid && j <= high){
		if(arr[i] < arr[j]){
			vec[s++] = arr[i++];
		}
		else{
			vec[s++] = arr[j++];
		}
	}
	while(i <= mid){
		vec[s++] = arr[i++];
	}
	while(j <= high){
		vec[s++] = arr[j++];
	}
	s = 0;
	for(int i = low; i <= high; i++){
		arr[i] = vec[s++];
	}
}