Submission #993649

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Source Code Expand

#include <iostream>
#include <vector>
using namespace std;

struct UnionFind {
    vector<int> data;
    UnionFind(int size) : data(size, -1) { }
    bool unionSet(int x, int y) {
        x = root(x); y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
            data[x] += data[y]; data[y] = x;
        }
        return x != y;
    }
    bool findSet(int x, int y) {
        return root(x) == root(y);
    }
    int root(int x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    int size(int x) {
        return -data[root(x)];
    }
};

int main(void)
{
    int N, M;
    cin >> N >> M;

    int K, L;
    vector<int> *lang = new vector<int>[M];
    UnionFind u(N);

    for (int i = 0; i < N; i++) {
        cin >> K;

        for (int j = 0; j < K; j++) {
            cin >> L;
            lang[L - 1].push_back(i);

            u.unionSet(lang[L - 1][0], i);
        }
    }

    delete[] lang;

    for (int i = 1; i < N; i++) {
        if (!u.findSet(0, i)) {
            cout << "NO" << endl;
            return 0;
        }
    }

    cout << "YES" << endl;
    return 0;
}

Submission Info

Judge Result