Submission #854507

#	Time	Username	Problem	Language	Result	Execution time	Memory
854507		IBory	Untitled (POI11_kon)	C++17	80 / 100	1249 ms	35964 KiB

Main

#include <bits/stdc++.h>
using namespace std;

const int MAX = 5005;
bool G[MAX][MAX];
int N, V[MAX], out[MAX], no[MAX], cnt;

void Fail() {
	cout << 0;
	exit(0);
}

void DFS(int cur) {
	cnt++;
	for (int next = 1; next <= N; ++next) {
		if (V[next] || !G[cur][next]) continue;
		V[next] = 1;
		DFS(next);
	}
}

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int ans = 1, E = 0;
	cin >> N;
	for (int i = 1; i <= N; ++i) {
		cin >> out[i];
		E += out[i];
		for (int j = 0; j < out[i]; ++j) {
			int n;
			cin >> n;
			G[i][n] = 1;
		}
	}

	int one = 0, comp = 0;
	vector<int> isolated;
	for (int i = 1; i <= N; ++i) {
		if (V[i]) continue;
		cnt = 0; V[i] = 1; DFS(i);
		if (cnt == 1) {
			one++;
			isolated.push_back(i);
		}
		else comp++;
	}

	if (comp > 1) Fail();

	int curNode = N - one;
	do {
		if (E == curNode * (curNode - 1)) break;
		int cand = 0, ec = 1e9;
		for (int i = 1; i <= N; ++i) {
			if (no[i]) continue;
			if (out[i] > 0 && ec > out[i]) {
				ec = out[i];
				cand = i;
			}
		}

		for (int i = 1; i <= N; ++i) {
			if (!G[cand][i]) continue;
			if (!G[i][cand]) Fail();
			out[i]--;
			G[cand][i] = 0;
			no[i] = 1;
		}

		if (!cand) Fail();

		out[cand] = 0;
		isolated.push_back(cand);
		E -= ec * 2;
	} while (--curNode);

	for (int i = 1; i <= N; ++i) {
		if (!out[i]) continue;
		int ok = 1;
		for (int n : isolated) {
			if (G[i][n]) {
				ok = 0;
				break;
			}
		}
		if (ok) ans++;
	}

	cout << ans;
	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 0 / 10