#include <bits/stdc++.h>
using namespace std;
const int nmax = 20;
int n,m;
int G[nmax + 5];
int d[(1<<nmax) + 5];
pair<int,int> t[(1<<nmax) + 5];
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
#ifdef home
freopen("nr.in","r",stdin);
freopen("nr.out","w",stdout);
#endif // home
cin>>n>>m;
for(int i=1; i<=m; i++)
{
int x,y;
cin>>x>>y;
--x, --y;
G[x] |= (1<<y);
G[y] |= (1<<x);
}
if(m != n - 1)
{
cout<<"NO"<<'\n';
return 0;
}
queue<int> q;
q.push((1<<n) - 1);
d[(1<<n) - 1] = 1;
t[(1<<n) - 1] = {-1,-1};
while(!q.empty())
{
int mask = q.front();
q.pop();
for(int i=0; i<n; i++)
{
int new_mask = 0;
for(int nod=0; nod<n; nod++)
{
if((mask & (1<<nod))!=0 && nod!=i)
{
new_mask |= G[nod];
}
}
if(!d[new_mask])
{
d[new_mask] = 1 + d[mask];
t[new_mask] = {i,mask};
q.push(new_mask);
}
}
}
if(!d[0])
{
cout<<"NO"<<'\n';
return 0;
}
vector<int> rez;
int mask = 0;
while(mask != -1)
{
if(t[mask].first != -1)
{
rez.push_back(t[mask].first + 1);
}
mask = t[mask].second;
}
reverse(rez.begin(),rez.end());
cout<<"YES"<<'\n';
/* cout<<rez.size()<<'\n';
for(auto it : rez)
{
cout<<it<<' ';
}
cout<<'\n';
*/
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2396 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2548 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2396 KB |
Unexpected end of file - int32 expected |
2 |
Halted |
0 ms |
0 KB |
- |