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;
}