Submission #453675

#	Time	Username	Problem	Language	Result	Execution time	Memory
453675		Hamed5001	Bosses (BOI16_bosses)	C++14	0 / 100	2 ms	460 KiB

bosses

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const int mxN = 5e3+10;
vector<int> edges[mxN];

int N;

int bfs(int st) {
	queue<pair<int, int>> q;
	vector<int> VIS(N+1, 0);
	q.push({1, st});

	int ret = 0;

	while(q.size()) {
		auto node = q.front();
		q.pop();
		if (VIS[node.second])
			continue;
		VIS[node.second] = 1;
		ret += node.first;

		for (auto c : edges[node.second]) {
			if (!VIS[c])
				q.push({node.first+1, c});
		}
	}

	for (int i = 1; i <= N; i++) {
		if (!VIS[i]) {
			ret = INT_MAX;
			break;
		}
	}
	return ret;
}

void solve() {
	cin >> N;
	for (int i = 1; i <= N; i++) {
		int K;
		cin >> K;
		for (int j = 0; j < K; j++) {
			int boss;
			cin >> boss;
			edges[boss].push_back(i);
		}
	}
	int ans = INT_MAX;
	for (int i = 1; i <= N; i++)
		ans = min(ans, bfs(i));


	if (ans == INT_MAX)
		ans = -1;
	cout << ans;
}

int main() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	solve();
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:64:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |  freopen("input.txt", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:65:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |  freopen("output.txt", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 22
• Subtask 2: 0 / 45
• Subtask 3: 0 / 33