837. 连通块中点的数量

Posted 2021-05-20 幽殇默

https://www.acwing.com/problem/content/description/839/

s[N] 数组的含义是 根节点所在集合的点的个数

#include<cstdio>
#include<iostream>
using namespace std;
const int N=1e5+10;
int p[N],s[N];
int find(int x)
{
    if(x!=p[x]) p[x]=find(p[x]);
    return p[x];
}
int main(void)
{
	int n,m; cin>>n>>m;
	for(int i=1;i<=n;i++) p[i]=i,s[i]=1;
	while(m--)
	{
		string op; cin>>op;
		if(op=="C")
		{
			int a,b; cin>>a>>b;
			if(find(a)==find(b)) continue;
			s[find(b)]+=s[find(a)];
			p[find(a)]=find(b);
		}
		if(op=="Q1")
		{
			int a,b; cin>>a>>b;
			if(find(a)==find(b)) cout<<"Yes"<<endl;
			else cout<<"No"<<endl;
		}
		if(op=="Q2")
		{
			int a; cin>>a;
			cout<<s[find(a)]<<endl;
		}
	}
	return 0;
}