#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
template<class T> bool ckmin(T& a, const T& b) {return a>b? a=b, true:false;}
template<class T> bool ckmax(T& a, const T& b) {return a<b? a=b, true:false;}
const int mod = 1e9+7, N = 23;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val)-1;}
int a[N], n, m, k;
bool iseq(int a, int b){
if(__builtin_popcount(a) == __builtin_popcount(b))return true;
int c1=0, c2=0;
while(a>0){
c1 += (a%3==1);
a/=3;
}
while(b>0){
c2 += (b%3==1);
b/=3;
}
return c1 == c2;
}
bool g[N][N];
int dp[1<<20][N];
void solve(int test_case){
int i, j;
cin >> n;
for(i=0;i<n;i++){
cin >> a[i];
}
for(i=0;i<n;i++){
for(j=0;j<n;j++){
if(i == j)continue;
if(iseq(a[i], a[j]))g[i][j] = 1;
}
}
for(i=1;i<(n);i++)dp[1<<i][i] = 1;
for(int mask = 3; mask < (1<<n); mask++){
for(i=0;i<n;i++){
if(mask&(1<<i)){
for(j=0;j<n;j++){
if(i != j && g[i][j] && (mask&(1<<j))){
dp[mask][i] += dp[mask^(1<<i)][j];
}
}
}
}
}
int ans = 0;
// for(i=0;i<(1<<n);i++)cout << dp[i][0] << '\n';
for(i=0;i<n;i++){
ans += dp[(1<<n)-1][i];
}
cout << ans << '\n';
return;
}
signed main(){
FASTIO;
#define MULTITEST 0
#if MULTITEST
int _T;
cin >> _T;
for(int T_CASE = 1; T_CASE <= _T; T_CASE++)
solve(T_CASE);
#else
solve(1);
#endif
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
364 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
