银河英雄传说(带权并查集)

Posted 2021-10-31 thusloop

银河英雄传说

//#pragma GCC optimize(2)
//#pragma GCC optimize(3,"Ofast","inline")
#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define pb push_back
#define pii pair<int,int>
#define ios ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
const int inf=2e18+100;
const int maxn=2e5+100;
int pre[maxn],sum[maxn],ans[maxn];
int find(int x)
{
	if(x!=pre[x])
	{
		int root=find(pre[x]);
		ans[x]+=ans[pre[x]];
		pre[x]=root;
	}
	return pre[x];
}
signed main()
{
	IOS
	for(int i=0;i<maxn;i++)
	{
		pre[i]=i;
		sum[i]=1;
	}
	int q;
	cin>>q;
	while(q--)
	{
		char op;
		int x,y;
		cin>>op>>x>>y;
		if(op=='M')
		{
			int fx=find(x);
			int fy=find(y);
			pre[fx]=fy;
			ans[fx]+=sum[fy];
			sum[fy]+=sum[fx];
		}
		else 
		{
			if(find(x)!=find(y))
			{
				cout<<"-1"<<"\\n";
			}
			else 
			{
				cout<<abs(ans[y]-ans[x])-1<<"\\n";
			}
		}
	}
}