#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 2e6+5;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll n, m;
bool can[25][25];
bool dp[MAXN];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
#ifdef Local
freopen("../IO/int.txt","r",stdin);
freopen("../IO/out.txt","w",stdout);
#endif
cin>>n>>m;
for(int i = 0; i < m; i++){
int a, b;
cin>>a>>b;
can[a - 1][b - 1] = 1;
can[b - 1][a - 1] = 1;
}
dp[0] = 1;
int ans = 0;
for(int i = 0; i < (1<<n); i++){
int cikari = (i & -i);
int yer = 0;
int tmp = cikari;
while(tmp){
tmp /= 2;
yer++;
}
yer--;
bool cn = 1;
for(int j = 0; j < n; j++){
if(((1<<j) & i) == 0){
continue;
}
if(can[j][yer]){
cn = 0;
break;
}
}
//cout<<i<<" "<<(i^cikari)<<endl;
if(cn == 0){
continue;
}
else if(dp[i^cikari]){
dp[i] = 1;
//cout<<i<<endl;
ans++;
}
}
cout<<ans<<endl;
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
380 KB |
Output is correct |
2 |
Correct |
4 ms |
504 KB |
Output is correct |
3 |
Correct |
14 ms |
376 KB |
Output is correct |
4 |
Correct |
16 ms |
376 KB |
Output is correct |
5 |
Correct |
21 ms |
504 KB |
Output is correct |
6 |
Correct |
31 ms |
632 KB |
Output is correct |
7 |
Correct |
33 ms |
632 KB |
Output is correct |
8 |
Correct |
61 ms |
800 KB |
Output is correct |
9 |
Correct |
71 ms |
1144 KB |
Output is correct |
10 |
Correct |
86 ms |
1260 KB |
Output is correct |