837. 连通块中点的数量

link

code

#include<bits/stdc++.h>
using namespace std;

const int N = 100010;

int fa[N], a[N];
int cnt[N];
int find(int x){
	if(x != fa[x]) fa[x] = find(fa[x]);
	return fa[x];
} 

void un(int x, int y){
	x = find(x);
	y = find(y);
	if(x != y){
		fa[y] = x;
		cnt[x] += cnt[y];
		
	}
}


int main(){
	int n, m;
	cin >> n >> m;
	for(int i = 1; i <= n; i++){
		fa[i] = i;
		cnt[i] = 1;
	}
	string s;
	int a, b;
	while(m--){
		cin >> s;
		if(s == "C"){
			cin >> a >> b;
			if(a != b) un(a,b);
		}else if(s == "Q1"){
			cin >> a >> b;
			if(a == b) cout <<"Yes"<<endl;
			else{
				a = find(a);
				b = find(b);
				if(a == b) cout <<"Yes"<<endl;
				else cout <<"No" <<endl;
			}
			
		}else{
			cin >> a;
			a = find(a);
			cout << cnt[a]<<endl;
		}
	}
	return 0;
}