Submission #478660

#	Time	Username	Problem	Language	Result	Execution time	Memory
478660		CSQ31	Newspapers (CEOI21_newspapers)	C++17	0 / 100	1 ms	468 KiB

newspapers

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 3e5+1;
int cnt[MAXN+1];
#define pb push_back
#define sz(a) (int)(a.size())
typedef long long int ll;
typedef vector<vector<int>>vii;
vii adj(1111);
int main()
{
	//the graph must be a tree
	//if have cycle then bob's possible space never decreases around the cycle
	//how to solve when have tree?
	
	//think about search space of bob
	//each turn a on state becomes off and turn everything incident to it on
	//alice can pick a node and off it
	//can she make everything off?
	int n,m;
	cin>>n>>m;
	for(int i=0;i<m;i++){
		int v,u;
		cin>>v>>u;
		adj[v].pb(u);
		adj[u].pb(v);
	}
	bool ok = 1;
	for(int i=1;i<=n;i++){
		if(sz(adj[i]) >1){
			for(int x:adj[i]){
				if(sz(adj[x]) > 1)ok = 0;
			}
		}
		
	}
	if(ok){
		cout<<"YES"<<'\n';
		//cout<<0;
	}
	else cout<<"NO";
	
	
}

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