#include<bits/stdc++.h>
using namespace std;
#define task "GEPPETTO"
#define lb lower_bound
#define ub upper_bound
#define ALL(v) (v).begin(),(v).end()
#define zs(v) (int)(v).size()
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define cntbit __builtin_popcountll
typedef long double ld;
typedef long long ll;
typedef pair<int,int> pii;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
const ll mod=1000000007; /// 998244353
const int base=311;
const int N=20+5;
int dd[25][25],cnt,n,m,q[N];
set<int> s[25];
void biot()
{
cin>>n>>m;
for(int i=1;i<=m;++i)
{
int u,v;
cin>>u>>v;
dd[u][v]=1;
dd[v][u]=1;
}
int ans=0;
for(int mask=0;mask<(1<<n);++mask)
{
int ok=1;
vector<int> v;
v.clear();
for(int i=1;i<=n;++i)
if(mask>>(i-1)&1) v.pb(i);
for(int i=0;i<zs(v);++i)
{
for(int j=i+1;j<zs(v);++j)
{
if(dd[v[i]][v[j]])
{
ok=0;
break;
}
}
if(!ok) break;
}
ans+=ok;
}
cout<<ans;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
if(fopen(task".inp","r"))
{
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
biot();
}
Compilation message
geppetto.cpp: In function 'int main()':
geppetto.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
63 | freopen(task".inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
geppetto.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
64 | freopen(task".out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
384 KB |
Output is correct |
2 |
Correct |
1 ms |
384 KB |
Output is correct |
3 |
Correct |
325 ms |
504 KB |
Output is correct |
4 |
Correct |
327 ms |
392 KB |
Output is correct |
5 |
Correct |
331 ms |
504 KB |
Output is correct |
6 |
Correct |
336 ms |
504 KB |
Output is correct |
7 |
Correct |
335 ms |
384 KB |
Output is correct |
8 |
Correct |
336 ms |
504 KB |
Output is correct |
9 |
Correct |
356 ms |
384 KB |
Output is correct |
10 |
Correct |
393 ms |
388 KB |
Output is correct |