#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 5e5 + 100;
const int mod = (int)1e9+7;
int n;
int a[maxn];
int g[22][22];
ll dp[1<<20][20];
int ter(int x) {
int cnt = 0;
while(x > 0) {
if(x % 3 == 1) cnt++;
x /= 3;
}
return cnt;
}
ll rec(int mask, int last) {
if(__builtin_popcount(mask) == n) {
return 1;
}
if(dp[mask][last] != -1) return dp[mask][last];
dp[mask][last] = 0;
for(int i = 0; i < n; i++) {
if(g[last][i] && !(mask & (1<<i))) {
dp[mask][last] += rec(mask|1<<i, i);
}
}
return dp[mask][last];
}
int main() {
ios_base::sync_with_stdio(false);
cin >> n;
for(int i = 0; i < n; i++) {
cin >> a[i];
}
for(int i = 0; i < n; i++) {
for(int j = 0; j < n; j++) {
if(__builtin_popcount(a[i]) == __builtin_popcount(a[j])) {
g[i][j] = 1;
} else {
if(ter(a[i]) == ter(a[j])) {
g[i][j] = 1;
}
}
}
}
memset(dp, -1, sizeof dp);
ll ans = 0;
vector<int>p(n);
for(int i = 0; i<n; i++) p[i] = i;
do{
int cur = 1;
for(int i = 1; i < n; i++) {
if(g[p[i]][p[i-1]] == 0) {
cur = 0;
break;
}
}
ans += cur;
}while(next_permutation(p.begin(), p.end()));
cout << ans << "\n";
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
60 ms |
164428 KB |
Output is correct |
| 2 |
Correct |
60 ms |
164412 KB |
Output is correct |
| 3 |
Correct |
70 ms |
164460 KB |
Output is correct |
| 4 |
Correct |
62 ms |
164340 KB |
Output is correct |
| 5 |
Correct |
61 ms |
164352 KB |
Output is correct |
| 6 |
Correct |
92 ms |
164584 KB |
Output is correct |
| 7 |
Correct |
79 ms |
164460 KB |
Output is correct |
| 8 |
Correct |
117 ms |
164464 KB |
Output is correct |
| 9 |
Correct |
84 ms |
164396 KB |
Output is correct |
| 10 |
Correct |
112 ms |
164396 KB |
Output is correct |
| 11 |
Execution timed out |
3066 ms |
164428 KB |
Time limit exceeded |
| 12 |
Halted |
0 ms |
0 KB |
- |
