Submission #881962

#	Time	Username	Problem	Language	Result	Execution time	Memory
881962		TAhmed33	Newspapers (CEOI21_newspapers)	C++98	8 / 100	1 ms	348 KiB

newspapers

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e3 + 25;
vector <int> adj[MAXN];
int n, m;
int cnt = 0;
void dfs (int pos, int par, int dep = 0) {
	if (dep == 3) {
		cnt++;
		return;
	}
	for (auto j : adj[pos]) if (j != par) dfs(j, pos, dep + 1);
}
int main () {
	cin >> n >> m;
	bool flag = 1;
	for (int i = 1; i <= m; i++) {
		int a, b;
		cin >> a >> b;
		if (a > b) swap(a, b);
		flag &= a + 1 == b;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
	if (m != n - 1) {
		cout << "NO\n";
		return 0;
	}
	if (flag) {
		cout << "YES\n";
		if (n == 1) {
			cout << "1\n1\n";
			return 0;
		}
		if (n == 2) {
			cout << "2\n2 2\n";
			return 0;
		}
		cout << 2 * (n - 2) << '\n';
		for (int i = 2; i < n; i++) cout << i << " ";
		for (int i = n - 1; i >= 2; i--) cout << i << " ";
		cout << '\n';
		return 0;
	}
	for (int i = 1; i <= n; i++) {
		if (adj[i].size() >= 3) {
			cnt = 0;
			dfs(i, -1);
			if (cnt >= 3) {
				cout << "NO\n";
				return 0;
			}
		}
	}
	cout << "YES\n";
}

• Subtask 1: 0 / 12
• Subtask 2: 8 / 8
• Subtask 3: 0 / 80