#include <bits/stdc++.h>
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define fast_io ios::sync_with_stdio(false);cin.tie(0);
#define what(x) cerr << #x << " is " << x << '\n';
#define kill(x) {cout << x << '\n'; return;}
#define all(x) (x).begin(), (x).end()
#define pii pair<int, int>
#define pb push_back
#define ll long long
#define F first
#define S second
const ll inf = 1e16, mod = 1e9 + 7, delta = 1e9 + 9, SQ = 350, P = 6065621;
using namespace std;
const int N = 60, LG = 21;
ll fac[N], inv[N], pw[N][N];
ll poww (ll a, ll b) {
if (!b) return 1;
if (b & 1) return a * poww(a * a % mod, b / 2) % mod;
return poww(a * a % mod, b / 2);
}
ll C(int n, int r) {
if (r > n || r < 0) return 0;
if (r == n || r == 0) return 1;
return fac[n] * inv[r] % mod * inv[n - r] % mod;
}
int main () {
fast_io;
fac[0] = 1;
for (int i = 1; i < N; i++) {
fac[i] = fac[i - 1] * i % mod;
inv[i] = poww(fac[i], mod - 2);
}
for (int i = 1; i < N; i++) {
pw[i][0] = 1;
for (int j = 1; j < N; j++) {
pw[i][j] = pw[i][j - 1] * i % mod;
}
}
int n;
cin >> n;
ll ans = 0;
for (int mask = 1; mask < (1 << n); mask++) {
int tmp = 0;
for (int i = 0; i < n; i++)
if (mask & (1 << i))
tmp += i + 1;
if (tmp > n) continue;
int cur = n;
ll res = 1;
for (int i = 0; i < n; i++) {
if (mask & (1 << i)) {
res = res * C(cur, i + 1) % mod;
cur -= (i + 1);
}
}
int b = __builtin_popcount(mask);
if (cur > 0) {
res = res * pw[n - b][cur] % mod;
}
if (b & 1) {
ans = (ans + res) % mod;
}
else {
ans -= res;
ans += mod;
ans %= mod;
}
}
cout << ans << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
500 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
500 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
356 KB |
Output is correct |
7 |
Correct |
1 ms |
484 KB |
Output is correct |
8 |
Correct |
1 ms |
344 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
484 KB |
Output is correct |
12 |
Correct |
2 ms |
348 KB |
Output is correct |
13 |
Correct |
2 ms |
480 KB |
Output is correct |
14 |
Correct |
4 ms |
344 KB |
Output is correct |
15 |
Correct |
8 ms |
348 KB |
Output is correct |
16 |
Correct |
15 ms |
344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
500 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
356 KB |
Output is correct |
7 |
Correct |
1 ms |
484 KB |
Output is correct |
8 |
Correct |
1 ms |
344 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
484 KB |
Output is correct |
12 |
Correct |
2 ms |
348 KB |
Output is correct |
13 |
Correct |
2 ms |
480 KB |
Output is correct |
14 |
Correct |
4 ms |
344 KB |
Output is correct |
15 |
Correct |
8 ms |
348 KB |
Output is correct |
16 |
Correct |
15 ms |
344 KB |
Output is correct |
17 |
Incorrect |
52 ms |
476 KB |
Output isn't correct |
18 |
Halted |
0 ms |
0 KB |
- |