L2-024 部落（简单的并查集）

传送门
本题是单纯的并查集(加个排序应该不算加吧）,很简单

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int f[10010];
vector<int> wait[10010];
vector<int> all;
int bet[10010];
int find(int x)
{
    if(f[x] != x) f[x] = find(f[x]);
    return f[x];
}

void Union(int a,int b)
           {
    int ra = find(a);
int rb = find(b);
               if(ra > rb)
               {
                   f[rb] = ra;
               }
    else f[ra] = rb;
           }

int main()
{
    int n;
    int ans = 0;
    cin>>n;
    for(int i = 0 ; i < n ; i++)
        {
            int k;cin>>k;
            for(int j = 0 ; j < k ; j ++)
            {
                int x;cin>>x;
                wait[i].push_back(x);
                all.push_back(x);
            }            
        }
    sort(all.begin(),all.end());
    all.erase(unique(all.begin(),all.end()) , all.end());
    int cnt = all.size();
    
	for(int i = 1; i <= cnt ; i++) f[i] = i;
    for(int i = 0 ; i < n ; i++)
        {
            for(int j = 0 ; j < wait[i].size() ; j++)
                {
                    if(j >= 1) Union(wait[i][j],wait[i][j-1]);
                }
        }
    for(int i = 1 ; i <= cnt; i++)
        {
            int x = find(i);
            //这里还可以用个bool数组来统计
            bet[x] ++;
            if(bet[x] == 1) ans++;
        }
        
    cout<<cnt<<" "<<ans<<endl;
        
    int k;cin>>k;
    while(k--)
        {
            int l,r;cin>>l>>r;
            if(f[l] != f[r]) cout<<"N"<<endl;
            else cout<<"Y"<<endl;
        }
    return 0;
}