https://codeforces.com/contest/1167/problem/C

题解：并查集

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
#define endl "\n"
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=500000+10;
const int M=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,p,l,r,u,v;
int ans,cnt,flag,temp,sum;
int pre[N],work[N];
char str;
struct node{};
int find(int x){return pre[x]==x?x:pre[x]=find(pre[x]);}
void marge(int x,int y){
    int fx=find(x);
    int fy=find(y);
    if(fx!=fy){
        if(work[fx]>work[fy]){
            pre[fy]=fx;
            work[fx]+=work[fy];
        }else{
            pre[fx]=fy;
            work[fy]+=work[fx];
        }
    }
}
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    //cout.tie(0);
    //scanf("%d",&t);
    //while(t--){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)pre[i]=i,work[i]=1;
    for(int i=1;i<=m;i++){
        scanf("%d",&k);
        if(k==0)
            continue;
        scanf("%d",&u);
        for(int j=2;j<=k;j++){
            scanf("%d",&v);
            marge(u,v);
        }
    }
    for(int i=1;i<=n;i++){
        cout<<work[find(i)]<<" ";
    }
    //}

#ifdef DEBUG
	printf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC);
#endif
    //cout << "Hello world!" << endl;
    return 0;
}