Submission #1456100

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Source Code Expand

#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "math.h"
#include "utility"
#include "string"
#include "map"
#include "unordered_map"
#include "iomanip"
#include "random"

using namespace std;
const long long int MOD = 1000000007;

long long int power(long long int x, long long int n, long long int M) {
	long long int tmp = 1;

	if (n > 0) {
		tmp = power(x, n / 2, M);
		if (n % 2 == 0) tmp = (tmp*tmp) % M;
		else tmp = (((tmp*tmp) % M)*x) % M;
	}
	return tmp;
}

long long int N, M, K, Q, W, H, L, R;
long long int ans;

class UnionFind {
	vector<int>parent;
	vector<int>rank;
public:
	UnionFind(int num) {
		num++;
		parent.resize(num);
		rank.resize(num);
		for (int i = 0; i < num; i++) {
			parent[i] = i;
			rank[i] = 0;
		}
	}
	int Find(int node) {
		if (parent[node] == node)return node;
		else return parent[node] = Find(parent[node]);
	}
	void Unite(int u, int v) {
		u = Find(u);
		v = Find(v);
		if (u == v)return;
		if (rank[u] < rank[v])parent[u] = v;
		else {
			parent[v] = u;
			if (rank[u] == rank[v])rank[u]++;
		}
	}
	bool Check_Same(int u, int v) {
		return Find(u) == Find(v);
	}
};

int main() {
	ios::sync_with_stdio(false);
	cin >> N >> M;
	UnionFind u(N + M + 1);
	vector<pair<int, int>>v;
	for (int i = 1; i <= N; i++) {
		cin >> K;
		for (int j = 0; j < K; j++) {
			cin >> Q;
			u.Unite(i, N + Q);
			v.push_back({ Q,i });
		}
	}
	sort(v.begin(), v.end());
	for (int i = 0; i < v.size() - 1; i++) {
		if (v[i].first == v[i + 1].first) {
			u.Unite(v[i].second, v[i + 1].second);
		}
	}
	ans = u.Find(1);
	for (int i = 2; i <= N; i++) {
		if (ans != u.Find(i)) {
			cout << "NO\n";
			return 0;
		}
	}
	cout << "YES\n";
	return 0;
}

Submission Info

Judge Result