#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define ll long long int
const ll N = 20+1 , INF = 1e18 , MOD = 1e9+7;
ll n;
vector<ll> a(N) , fact(N);
ll dp[(1ll<<N)][N];
ll go(ll mask , ll last){
if(mask == ((1ll<<n)-1)) return 0;
if(dp[mask][last] != -1) return dp[mask][last];
ll ans = 0;
for(ll i = 0; i < n; i++){
if(mask&(1ll<<i)) continue;
if(last != 0 && __builtin_popcountll(last) == __builtin_popcountll(a[i])) ans += fact[n-__builtin_popcount(mask)-1];
else ans += go(mask|(1ll<<i),i);
}
return dp[mask][last] = ans;
}
void solve(){
cin >> n;
for(ll i = 0; i < n; i++) cin >> a[i];
fact[0] = 1;
for(ll i = 1; i <= max(n,18ll); i++) fact[i] = i*fact[i-1];
memset(dp,-1,sizeof dp);
cout << go(0,0);
}
int main(){
fast;
ll tc = 1;
// cin >> tc;
while(tc--) solve();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
108 ms |
262144 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
