PAT Advanced 1118 【Birds in Forest】（25 ）

分析：PAT之日常并查集。

#include<iostream>
#include<cstdio>
using namespace std;
const int maxn = 1e4+10;
int father[maxn], vis[maxn];
int getF(int x){
	return x == father[x] ? x : father[x] = getF(father[x]);
}
void merge(int a, int b){
	int fa = getF(a), fb = getF(b);
	if(fa != fb) father[fa] = fb;
}
void init(){
	for(int i = 1; i<=maxn; i++){
		father[i] = i;
	}
}
int getTreeNum(int n){
	int cnt = 0;
	for(int i = 1; i<=n; i++){
		int fa = getF(i);
		father[i] = fa;
		if(!vis[fa]){
			vis[fa] = 1;
			cnt++;
		}
	}
	return cnt;
}
int main(){
//	freopen("aa.txt", "r", stdin);
	int n, u, v, num, tot = 0;
	ios::sync_with_stdio(false);
	cin >> n;
	init();
	for(int i = 0; i<n; i++){
		cin >> num >> u;
		tot = max(tot, u);
		for(int j = 1; j<num; j++){
			cin >> v;
			merge(u, v);
			tot = max(tot, v);
		}
	}
	int treeNum = getTreeNum(tot);
	cout << treeNum << " " << tot << '\n';
	int k;
	cin >> k;
	for(int i = 0; i<k; i++){
		cin >> u >> v;
		father[u] == father[v] ? cout << "Yes\n" : cout << "No\n";
	}
	return 0;
}