是我记忆化搜索的练习题，结果本来打算写暴力看看分数，结果 AC 了？

#include <bits/stdc++.h>
using namespace std;
int main()
{
	int t,p;
	cin >> t >> p;
	while(t--)
	{
		int x,y;
		cin >> x >> y;
		map<pair<int,int>,bool> mp;
		int ans = 0;
		while(true)
		{
			x = (x+y) % p;
			if(x == 0)
			{
				ans = 1;
				break;
			}
			if(mp.count({x,y}))
			{
				ans = 3;
				break;
			}
			mp[{x,y}] = true;
			y = (x+y) % p;
			if(y == 0)
			{
				ans = 2;
				break;
			}
			if(mp.count({x,y}))
			{
				ans = 3;
				break;
			}
			mp[{x,y}] = true;
		}
		if(ans == 3)cout << "error\n";
		else cout << ans << "\n";
	}
	return 0;
}

https://www.luogu.com.cn/record/196162466