Submission #992267

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Source Code Expand

#include <iostream>
#include <sstream>
#include <iomanip>
#include <cstdio>
#include <cassert>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
#include <list>
#include <deque>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <tuple>
#include <queue>
#include <stack>
#include <functional>
#include <utility>
#include <complex>
#include <bitset>
#include <numeric>
using namespace std;

#define REP(i,n) for(int (i)=0; (i)<(n) ;++(i))
#define REPN(i,a,n) FOR((i),(a),(a)+(n))
#define FOR(i,a,b) for(int (i)=(a); (i)<(b) ;++(i))
#define PB push_back
#define MP make_pair
#define SE second
#define FI first
#define DBG(a) cerr<<(a)<<endl;
#define ALL(v) (v).begin(),(v).end()
typedef long long LL;  typedef pair<LL, LL> PLL; typedef vector<LL> VLL;
const LL LINF=334ll<<53; const int INF=15<<26; const LL MOD=1E9+7;


typedef pair<int,int> pii;
struct Edge{
    int from,to;
    LL cost;
    Edge(int from,int to, LL cost)
        : from(from),to(to),cost(cost) {};
};
typedef vector<vector<Edge>> Graph;
int vis[100010];

void dfs(int s,vector<vector<int>> &l,vector<vector<int>> &p){
    for(auto x : p[s]){
        for(auto y:l[x]){
            if(vis[y]==0){
                vis[y]=1;
                dfs(y,l,p);
            }
        }
    }
    return;
}
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n,m;
    cin >> n>> m;
    Graph G(n);
    vector<vector<int>> l(m+1),p(n+1);
    REP(i,n){
        int tmp,tmp2;
        cin >> tmp;
        tmp--;
            REP(j,tmp){
                cin >> tmp2;
                tmp2--;
                l[tmp2].push_back(i);
                p[i].push_back(tmp2);
            }
    }

    dfs(0,l,p);
    bool ans=true;
    REP(i,n){
        if(vis[i]==0){
            ans=false;
            break;
        }
    }
    if(ans)cout << "YES" <<endl;
    else cout << "NO"<<endl;


    return 0;
}

Submission Info

Judge Result