Submission #992779

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Source Code Expand

#include <iostream>
#include <vector>

int main() {
	int n, m;
	int c, l;
	static std::vector<int> v[2000];
	static int a[2000][2000];
	std::cin >> n >> m;
	for (int i = 0; i < n; i++) {
		std::cin >> c;
		for (int j = 0; j < c; j++) {
			std::cin >> l;
			v[l - 1].push_back(i);
		}
	}

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			a[i][j] = false;
		}
	}
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < v[i].size(); j++) {
			for (int k = 0; k < v[i].size(); k++) {
				a[v[i][j]][v[i][k]] = true;
			}
		}
	}

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (a[i][j]) {
				for (int k = 0; k < n; k++) {
					a[i][k] |= a[j][k];
				}
			}
		}
	}

	bool r = true;
	for (int i = 0; i < n; i++) {
		r &= a[0][i];
	}
	if (r) {
		std::cout << "YES" << std::endl;
	} else {
		std::cout << "NO" << std::endl;
	}
	return 0;
}

Submission Info

Judge Result