Submission #7954189

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Source Code Expand

#include<iostream>
#include<iomanip>
#include<cstdio>
#include<string>
#include<cstring>
#include<climits>
#include<algorithm>
#include<vector>
#include<cmath>
#include<map>
#include<set>
#include<stack>
#include<queue>
#include<deque>
#include<tuple>
#include<list>
#include<unordered_map>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vii vector<int>
#define vll vector<ll>
#define lb lower_bound
#define pb push_back
#define mp make_pair
#define fi first
#define sc second
#define rep(i,n) for(ll i=0;i<n;i++)
#define rep2(i,a,b) for(ll i=a;i<b;i++)
#define repr(i,n) for(ll i=n-1;i>=0;i--)
#define all(x) x.begin(),x.end()
#define LB(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define UB(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
#define ERASE(v) v.erase(unique(v.begin(),v.end()),v.end())
// #define int ll
using namespace std;
const int INF (1 << 30);
const ll LLINF (1LL << 55LL);
const int MOD = 1000000007;
const int MAX = 510000;
const double pi = acos(-1);
const double eps = 1e-9;


struct UnionFind {
    vector<ll> par;
        
    UnionFind(ll n) : par(n, -1) { }
    void init(ll n) { par.assign(n, -1); }
    
    ll find(ll x) {
        if (par[x] < 0) return x;
        else return par[x] = find(par[x]);
    }
    
    bool same(ll x, ll y) {
        return find(x) == find(y);
    }
    
    bool unite(ll x, ll y) {
        x = find(x); y = find(y);
        if (x == y) return false;
        if (par[x] > par[y]) swap(x, y);
        par[x] += par[y];
        par[y] = x;
        return true;
    }
    
    ll size(ll x) {
        return -par[find(x)];
    }

    void print(ll x){
        rep(i,x){
            cout<<par[i]<<endl;
        }
        return ;
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    ll n,m,v[100010];
    cin>>n>>m;
    vll l[100010];
    UnionFind uf(n);
    vector<pll> G;

    rep(i,n){
        cin>>v[i];
        rep(j,v[i]){
            ll b;
            cin>>b;
            l[b].push_back(i);
        }
    }
    rep2(i,1,m+1){
        if(l[i].size()<=1) continue;
        rep(j,l[i].size()){
            if(j==l[i].size()-1) continue;
            uf.unite(l[i][j],l[i][j+1]);
        }
    }
    if(uf.size(0)==n) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}

Submission Info

Judge Result