Submission #2835354

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

#define int long long
const double PI = 3.14159265358979323846;
typedef vector<int> vint;
typedef pair<int, int> pint;
int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

int N, M;
int K[110000];
vint L[110000], G[220000];
bool visited[220000];
void dfs(int x) {
    visited[x] = true;
    for (int i = 0; i < G[x].size(); i++) {
        if (!visited[G[x][i]]) dfs(G[x][i]);
    }
}

signed main() {
    cin >> N >> M;
    for (int i = 0; i < N; i++) {
        cin >> K[i];
        L[i].resize(K[i]);
        for (int j = 0; j < K[i]; j++) {
            cin >> L[i][j];
            G[i].push_back(110000 + L[i][j]);
            G[110000 + L[i][j]].push_back(i);
        }
    }
    dfs(0);
    for (int i = 0; i < N; i++) {
        if (!visited[i]) {
            cout << "NO" << endl;
            return 0;
        }
    }
    cout << "YES" << endl;

    return 0;
}

Submission Info

Judge Result