9-归并排序

#include<iostream>
#include <cstring>
#include <cstdlib>
using namespace std;

int n;

void Merge(int *r1, int low, int mid, int high)
{
//	int *r2 = new int(high  - low + 1);
	int *r2;
	r2 = (int *)malloc(sizeof(int) * (high - low + 1));
	int i = low, j = mid + 1, k = 0;

	while(i <= mid && j <= high)
	{
		if(r1[i] < r1[j])
			r2[k++] = r1[i++];
		else
			r2[k++] = r1[j++];
	}

	while(i <= mid)
	{
		r2[k++] = r1[i++];
	}

	while(j <= high)
	{
		r2[k++] = r1[j++];
	}

	for(i = 0, j = low; i < k && j <= high; i++)
		r1[j++] = r2[i];
//	cout << "test: " << low << " " << high << endl;
//	for(int i = 0; i < k; i++){
//		cout << r2[i] << " " ;
//	}
//	cout << endl;
}

void Msort(int *r1, int low, int high)
{

	if(low < high)
	{
		int mid = (low + high) / 2;
		Msort(r1, low, mid);
		Msort(r1, mid + 1, high);
		Merge(r1, low, mid, high);
	}
	
}

int main()
{
	cin >> n;
	int num[1000];
	for(int i = 1; i <= n; i++)
		cin >> num[i];

	Msort(num, 1, n);
	for(int i = 1; i <=n; i++)
		cout << num[i] << " ";
}