#include <bits/stdc++.h>
using namespace std;
#define sp << " " <<
#define int long long
#define vi vector<int>
#define F(xxx,yyy) for (int xxx=1;xxx<=yyy;xxx++)
#define pii pair<int,int>
const int N = 2e5+1;
const int MOD = 1e9+7;
int mult(int x,int y) {return ((x%MOD)*(y%MOD))%MOD;}
int expo(int x,int y) {
if (!y) return 1;
int e = expo(x,y/2);
e = mult(e,e);
if (y&1) e = mult(e,x);
return e;
}
int divide(int x,int y) {return mult(x,expo(y,MOD-2));}
int add(int x,int y) {return ((x+y)>=MOD?x+y-MOD:x+y);}
vi fact(N,1);
int nck(int x,int y) {
if (x < y) return 0;
if (x < 0) return 0;
return divide(fact[x],mult(fact[y],fact[x-y]));
}
void solve() {
for (int i=2;i<=N;i++) fact[i] = mult(fact[i-1],i);
int n;
cin >> n;
int lim = (1<<n);
vi dp(lim);
for (int mask = 1;mask<lim;mask++) {
int sm = 0;
int p = 1,c = 0;
for (int i=0;i<n;i++) {
if (mask & (1<<i)) {
p = mult(p,nck(n-sm,i+1));
sm+=i+1;
c++;
}
}
p = mult(p,expo(n-c,n-sm));
dp[mask] = p;
}
int ans = 0;
for (int i=1;i<lim;i++) {
int pc = __builtin_popcountll(i);
if (pc%2) ans = add(ans,dp[i]);
else ans = add(ans,MOD-dp[i]);
}
cout << ans << endl;
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Local
freopen("in","r",stdin);
freopen("out","w",stdout);
#endif
int t = 1;
//cin >> t;
F(i,t) solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
1880 KB |
Output is correct |
2 |
Correct |
3 ms |
1884 KB |
Output is correct |
3 |
Correct |
3 ms |
2032 KB |
Output is correct |
4 |
Correct |
3 ms |
1884 KB |
Output is correct |
5 |
Correct |
3 ms |
1884 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
1880 KB |
Output is correct |
2 |
Correct |
3 ms |
1884 KB |
Output is correct |
3 |
Correct |
3 ms |
2032 KB |
Output is correct |
4 |
Correct |
3 ms |
1884 KB |
Output is correct |
5 |
Correct |
3 ms |
1884 KB |
Output is correct |
6 |
Correct |
4 ms |
1884 KB |
Output is correct |
7 |
Correct |
4 ms |
1884 KB |
Output is correct |
8 |
Correct |
6 ms |
1884 KB |
Output is correct |
9 |
Correct |
8 ms |
2028 KB |
Output is correct |
10 |
Correct |
15 ms |
2168 KB |
Output is correct |
11 |
Correct |
28 ms |
2268 KB |
Output is correct |
12 |
Correct |
54 ms |
2392 KB |
Output is correct |
13 |
Correct |
108 ms |
2908 KB |
Output is correct |
14 |
Correct |
220 ms |
3932 KB |
Output is correct |
15 |
Correct |
449 ms |
5976 KB |
Output is correct |
16 |
Correct |
926 ms |
10216 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
1880 KB |
Output is correct |
2 |
Correct |
3 ms |
1884 KB |
Output is correct |
3 |
Correct |
3 ms |
2032 KB |
Output is correct |
4 |
Correct |
3 ms |
1884 KB |
Output is correct |
5 |
Correct |
3 ms |
1884 KB |
Output is correct |
6 |
Correct |
4 ms |
1884 KB |
Output is correct |
7 |
Correct |
4 ms |
1884 KB |
Output is correct |
8 |
Correct |
6 ms |
1884 KB |
Output is correct |
9 |
Correct |
8 ms |
2028 KB |
Output is correct |
10 |
Correct |
15 ms |
2168 KB |
Output is correct |
11 |
Correct |
28 ms |
2268 KB |
Output is correct |
12 |
Correct |
54 ms |
2392 KB |
Output is correct |
13 |
Correct |
108 ms |
2908 KB |
Output is correct |
14 |
Correct |
220 ms |
3932 KB |
Output is correct |
15 |
Correct |
449 ms |
5976 KB |
Output is correct |
16 |
Correct |
926 ms |
10216 KB |
Output is correct |
17 |
Incorrect |
909 ms |
4072 KB |
Output isn't correct |
18 |
Halted |
0 ms |
0 KB |
- |