#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);
bool ok = 1,vis[1111];
void dfs(int v,int u){
vis[v] = 1;
for(int x:adj[v]){
if(x == u)continue;
if(vis[x])ok = 0;
else dfs(x,v);
}
}
int d = 0;
int dfs2(int v,int u){
int d1 = 0,d2 = 0;
vector<int>c;
for(int x:adj[v]){
if(x == u)continue;
int d = dfs2(x,v)+1;
c.pb(d);
if(d > d1){
d2=d1;
d1=d;
}else if(d > d2){
d2=d;
}
}
int cnt = 0;
for(int x:c)if(x > 1)cnt++;
if(cnt>=3)ok = 0;
d=max(d,d1+d2);
return d1;
}
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);
}
dfs(1,0);
if(ok){
dfs2(1,0);
cout<<"YES"<<'\n';
cout<<2<<'\n';
cout<<1<<" "<<1;
}
else cout<<"NO";
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Partially correct |
0 ms |
204 KB |
Provide a successful but not optimal strategy. |
2 |
Correct |
1 ms |
332 KB |
Output is correct |
3 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
4 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
5 |
Correct |
1 ms |
332 KB |
Output is correct |
6 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
7 |
Correct |
0 ms |
332 KB |
Output is correct |
8 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
9 |
Incorrect |
0 ms |
332 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Partially correct |
1 ms |
204 KB |
Provide a successful but not optimal strategy. |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
4 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
5 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
6 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
7 |
Partially correct |
1 ms |
204 KB |
Failed to provide a successful strategy. |
8 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
9 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
10 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
11 |
Partially correct |
1 ms |
460 KB |
Failed to provide a successful strategy. |
12 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
13 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
14 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
15 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
16 |
Partially correct |
2 ms |
460 KB |
Failed to provide a successful strategy. |
17 |
Partially correct |
1 ms |
460 KB |
Failed to provide a successful strategy. |
18 |
Partially correct |
1 ms |
460 KB |
Failed to provide a successful strategy. |
19 |
Partially correct |
1 ms |
460 KB |
Failed to provide a successful strategy. |
20 |
Partially correct |
1 ms |
460 KB |
Failed to provide a successful strategy. |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Partially correct |
0 ms |
204 KB |
Provide a successful but not optimal strategy. |
2 |
Correct |
1 ms |
332 KB |
Output is correct |
3 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
4 |
Partially correct |
0 ms |
332 KB |
Failed to provide a successful strategy. |
5 |
Correct |
1 ms |
332 KB |
Output is correct |
6 |
Partially correct |
0 ms |
204 KB |
Failed to provide a successful strategy. |
7 |
Correct |
0 ms |
332 KB |
Output is correct |
8 |
Partially correct |
1 ms |
332 KB |
Failed to provide a successful strategy. |
9 |
Incorrect |
0 ms |
332 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |