/*DavitMarg*/
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <stack>
#include <cassert>
#include <iterator>
#include <bitset>
#include <fstream>
#define mod 998244353ll
#define LL long long
#define LD long double
#define MP make_pair
#define PB push_back
#define all(v) v.begin(),v.end()
using namespace std;
LL binpow(LL a,int n)
{
if(n==0)
return 1;
if(n%2==0)
return binpow(a*a%mod,n/2);
return a*binpow(a,n-1)%mod;
}
bool inMask(int a,int mask)
{
return (bool)((1<<a)&mask);
}
int n,m;
int ans[(1<<18)+10],cnt[(1<<18)+10];
vector<pair<int,int>> p;
vector<int> g[20];
bool isEdge[(1<<18)+10];
int main()
{
cin>>n>>m;
for(int i=1;i<=m;i++)
{
int a,b;
cin>>a>>b;
a--;
b--;
g[a].PB(b);
g[b].PB(a);
p.PB(MP(a,b));
}
//for(int i=0;i<n;i++)
// ans[(1<<i)]=1;
for(int mask=0;mask<(1<<n);mask++)
{
for(int i=0;i<n;i++)
{
if(((1<<i)&mask)==0)
continue;
cnt[mask]++;
for(int j=0;j<g[i].size();j++)
isEdge[mask]|=inMask(g[i][j],mask);
}
//cout<<"cnt["<<mask<<"]="<<cnt[mask]<<endl;
}
ans[0]=1;
for(int mask=1;mask<(1<<n);mask++)
{
int s=mask;
while(s>0)
{
if(isEdge[s])
continue;
//cout<<"cnt["<<(mask^s)<<"]="<<cnt[mask^s]<<endl;
//cout<<"!ns["<<(mask^s)<<"]="<<ans[mask^s]<<endl;
if(cnt[s]%2==1)
ans[mask]+=ans[mask^s];
else
ans[mask]+=mod-ans[mask^s];
ans[mask]%=mod;
s=(s-1)&mask;
}
//cout<<"ans["<<mask<<"]="<<ans[mask]<<endl;
}
LL answ=ans[(1<<n)-1];
answ*=(LL)m;
answ%=mod;
answ*=binpow(2,mod-2);
answ%=mod;
cout<<answ<<endl;
return 0;
}
/*
3 1
1 2
*/
Compilation message
amusementpark.cpp: In function 'int main()':
amusementpark.cpp:67:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<g[i].size();j++)
~^~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
376 KB |
Output is correct |
2 |
Execution timed out |
3075 ms |
256 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
376 KB |
Output is correct |
2 |
Execution timed out |
3075 ms |
256 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
376 KB |
Output is correct |
2 |
Execution timed out |
3075 ms |
256 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
376 KB |
Output is correct |
2 |
Execution timed out |
3075 ms |
256 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
376 KB |
Output is correct |
2 |
Execution timed out |
3075 ms |
256 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |