Submission #992604

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Source Code Expand

#include <algorithm>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#define SREP(s,i,m) for(unsigned int i = s; i < m; ++i)
#define REP(i,m) SREP(0,i,m)
using namespace std;

#ifdef _MSC_VER
using LONG = __int64;
using ULONG = unsigned __int64;
#else
using LONG = long long int;
using ULONG = unsigned long long int;
#endif

void search(vector<vector<int>> &G, vector<bool> &visited, int i) {
  visited[i] = true;
  REP(j, G[i].size()) {
    if (!visited[G[i][j]]) {
      search(G, visited, G[i][j]);
    }
  }
}

// 二乗を計算する。
int sq(int x) { return x * x; }
int main(void) {
  int N, M;
  cin >> N >> M;
  vector<vector<int>> L(N);
  vector<set<int>> speaker(M + 1);
  REP(i, N) {
    int K;
    cin >> K;
    L[i].resize(K);
    REP(j, K) {
      cin >> L[i][j];
      speaker[L[i][j]].insert(i);
    }
  }
  vector<vector<int>> G(N);
  REP(i, N) {
    set<int> pre;
    REP(j, L[i].size()) {
      for(auto k : speaker[L[i][j]]) {
        pre.insert(k);
      }
    }
    for (auto j : pre) {
      G[i].push_back(j);
    }
  }

  vector<bool> visited(N, false);
  search(G, visited, 0);
  bool ok = true;
  REP(i, N) {
    if (!visited[i]) ok = false;
  }
  cout << (ok ? "YES" : "NO") << endl;

  return 0;
}

Submission Info

Judge Result