Submission #992194

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <cstring>
#include <string>
#include <numeric>
#include <limits>
#include <set>
#include <map>
using namespace std;

struct union_find {
    std::vector<int> parent;
    int __size;
    union_find(int size_) : parent(size_, -1), __size(size_) {}
    void unite(int x, int y) {
        if ((x = find(x)) != (y = find(y))) {
            if (parent[y] < parent[x]) swap(x, y);
            parent[x] += parent[y];
            parent[y] = x;
            __size--;
        }
    }
    bool is_same(int x, int y) { return find(x) == find(y); }
    int find(int x) { return parent[x] < 0 ? x : parent[x] = find(parent[x]); }
    int size(int x) { return -parent[find(x)]; }
    int size() { return __size; }
};

int n, m;
vector<int> lang[100010];

int main() {
    while (cin >> n >> m) {
        for (int i = 0; i < 100010; i++) {
            lang[i].clear();
        }
        union_find uf(n);
        for (int i = 0; i < n; i++) {
            int k;
            cin >> k;
            for (int j = 0; j < k; j++) {
                int l;
                cin >> l;
                --l;
                lang[l].push_back(i);
            }
        }
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < (int)lang[i].size() - 1; j++) {
                int a = lang[i][j];
                int b = lang[i][j + 1];
                uf.unite(a, b);
            }
        }
        cout << (uf.size() == 1 ? "YES" : "NO") << endl;
    }
}

Submission Info

Judge Result