1035 插入与归并

1035 插入与归并

参考了大神的代码https://www.liuchuo.net/archives/503

#include <iostream>
#include <vector>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <math.h>
#include <string>
using namespace std;

int main()
{
	int n;
	cin >> n;
	//插入还是归并
	vector<int>first(n);
	vector<int>middle(n);
	for (int i = 0; i < n; i++)
	{
		cin >> first[i];
	}
	for (int i = 0; i < n; i++)
	{
		cin >> middle[i];
	}
	int i = 0, j = 0;
	//找到顺序排序的最后一个数字
	while (i<n-1 && middle[i]<=middle[i+1])
	{
		i++;
	}
	//如果是插入排序，后面的数组与原来的一样
	j = i + 1;
	while (j<n && middle[j]==first[j])
	{
		j++;
	}
	if (j==n)
	{
		cout << "Insertion Sort"<<endl;
		sort(first.begin(), first.begin() + i + 2);
	}
	else
	{
		cout << "Merge Sort" << endl;
		//归并排序
		int k = 1, flag = 1;
		while (flag)
		{
			flag = 0;
			for ( i = 0; i < n; i++)
			{
				if (first[i] != middle[i])
					flag = 1;
			}
			k = k * 2;
			for (i = 0; i < n/k; i++)
			{
				sort(first.begin() + i * k, first.begin() + (i + 1) * k);
			}
			sort(first.begin() + n / k * k, first.begin() + n);
		}
	}	
	for ( j = 0; j< n; j++)
	{
		if (j!=0)
		{
			printf(" ");
		}
		printf("%d", first[j]);
	}
	return 0;
}