Submission #992970

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Source Code Expand

#include <iostream>
#include <vector>
#include <stdlib.h>
#include <math.h>
#include <algorithm>
#include <queue>
using namespace std;

bool ok[1001][1001];

int main() {

	int l[1000];
	bool reached[1001];
	int n, m;
	cin >> n >> m;

	int k;

	for (int i = 0; i < m; i++) {
		reached[i] = true;
	}

	for (int i = 0; i < n; i++) {
		cin >> k;
		for (int x = 0; x < k; x++) {
			cin >> l[x];
			reached[l[x]] = false;
		}
		// sort(l, l + k);

		for (int dist = 0; dist < k-1; dist++) {
			for (int sorce = dist + 1; sorce < k; sorce++) {
				int x = l[dist];
				int y = l[sorce];
				ok[x][y] = true;
				ok[y][x] = true;
			}
		}
	}

	queue<int> queue;
	queue.push(1);
	reached[1] = true;
	while (!queue.empty()) {
		int target;
		target = queue.front();
		queue.pop();
		for (int i = 1; i <= m; i++) {
			if (ok[target][i] == false) {
				continue;
			}
			if (reached[i] == true) {
				//ignore
			}
			else {
				queue.push(i);
				reached[i] = true;
			}
		}
	}

	for (int i = 1; i <= m; i++) {
		if (reached[i] == false) {
			cout << "NO" << endl;
			return 0;
		}
	}
	cout << "YES" << endl;
	return 0;
}

Submission Info

Judge Result