#include <bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
typedef long long lint;
typedef pair<int, int> pi;
const int mod = 1e9 + 7;
lint fact[MAXN], invf[MAXN];
lint bino(int x, int y){
return fact[x] * (invf[y] * invf[x-y] % mod) % mod;
}
lint ipow(int x, int p){
lint ret = 1, piv = x;
while(p){
if(p & 1) ret = ret * piv % mod;
piv = piv * piv % mod;
p >>= 1;
}
return ret;
}
int main(){
int n, k;
cin >> n >> k;
k--;
fact[0] = invf[0] = 1;
for(int i=1; i<=n+1; i++){
fact[i] = fact[i-1] * i % mod;
invf[i] = ipow(fact[i], mod - 2);
}
lint ans = 0;
for(int i=0; i<=k; i++) ans += (i % 2 ? -1 : 1) * bino(n+1, i) * ipow(k - i + 1, n) % mod;
ans = ((ans % mod) + mod) % mod;
cout << ans << endl;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
256 KB |
Output is correct |
| 2 |
Correct |
3 ms |
256 KB |
Output is correct |
| 3 |
Correct |
2 ms |
256 KB |
Output is correct |
| 4 |
Correct |
3 ms |
256 KB |
Output is correct |
| 5 |
Correct |
2 ms |
256 KB |
Output is correct |
| 6 |
Correct |
3 ms |
256 KB |
Output is correct |
| 7 |
Correct |
2 ms |
304 KB |
Output is correct |
| 8 |
Correct |
3 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
256 KB |
Output is correct |
| 10 |
Correct |
3 ms |
256 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
256 KB |
Output is correct |
| 2 |
Correct |
3 ms |
256 KB |
Output is correct |
| 3 |
Correct |
2 ms |
256 KB |
Output is correct |
| 4 |
Correct |
3 ms |
256 KB |
Output is correct |
| 5 |
Correct |
2 ms |
256 KB |
Output is correct |
| 6 |
Correct |
3 ms |
256 KB |
Output is correct |
| 7 |
Correct |
2 ms |
304 KB |
Output is correct |
| 8 |
Correct |
3 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
256 KB |
Output is correct |
| 10 |
Correct |
3 ms |
256 KB |
Output is correct |
| 11 |
Correct |
2 ms |
256 KB |
Output is correct |
| 12 |
Correct |
2 ms |
256 KB |
Output is correct |
| 13 |
Correct |
3 ms |
256 KB |
Output is correct |
| 14 |
Correct |
3 ms |
384 KB |
Output is correct |
| 15 |
Correct |
3 ms |
128 KB |
Output is correct |
| 16 |
Correct |
3 ms |
384 KB |
Output is correct |
| 17 |
Correct |
3 ms |
256 KB |
Output is correct |
| 18 |
Correct |
2 ms |
256 KB |
Output is correct |
| 19 |
Correct |
2 ms |
256 KB |
Output is correct |
| 20 |
Correct |
2 ms |
256 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
256 KB |
Output is correct |
| 2 |
Correct |
3 ms |
256 KB |
Output is correct |
| 3 |
Correct |
2 ms |
256 KB |
Output is correct |
| 4 |
Correct |
3 ms |
256 KB |
Output is correct |
| 5 |
Correct |
2 ms |
256 KB |
Output is correct |
| 6 |
Correct |
3 ms |
256 KB |
Output is correct |
| 7 |
Correct |
2 ms |
304 KB |
Output is correct |
| 8 |
Correct |
3 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
256 KB |
Output is correct |
| 10 |
Correct |
3 ms |
256 KB |
Output is correct |
| 11 |
Correct |
2 ms |
256 KB |
Output is correct |
| 12 |
Correct |
2 ms |
256 KB |
Output is correct |
| 13 |
Correct |
3 ms |
256 KB |
Output is correct |
| 14 |
Correct |
3 ms |
384 KB |
Output is correct |
| 15 |
Correct |
3 ms |
128 KB |
Output is correct |
| 16 |
Correct |
3 ms |
384 KB |
Output is correct |
| 17 |
Correct |
3 ms |
256 KB |
Output is correct |
| 18 |
Correct |
2 ms |
256 KB |
Output is correct |
| 19 |
Correct |
2 ms |
256 KB |
Output is correct |
| 20 |
Correct |
2 ms |
256 KB |
Output is correct |
| 21 |
Correct |
3 ms |
384 KB |
Output is correct |
| 22 |
Correct |
3 ms |
384 KB |
Output is correct |
| 23 |
Correct |
3 ms |
304 KB |
Output is correct |
| 24 |
Correct |
3 ms |
384 KB |
Output is correct |
| 25 |
Correct |
2 ms |
256 KB |
Output is correct |
| 26 |
Correct |
3 ms |
384 KB |
Output is correct |
| 27 |
Correct |
3 ms |
384 KB |
Output is correct |
| 28 |
Correct |
3 ms |
384 KB |
Output is correct |
| 29 |
Correct |
3 ms |
256 KB |
Output is correct |
| 30 |
Correct |
2 ms |
384 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
2 ms |
256 KB |
Output is correct |
| 2 |
Correct |
3 ms |
256 KB |
Output is correct |
| 3 |
Correct |
2 ms |
256 KB |
Output is correct |
| 4 |
Correct |
3 ms |
256 KB |
Output is correct |
| 5 |
Correct |
2 ms |
256 KB |
Output is correct |
| 6 |
Correct |
3 ms |
256 KB |
Output is correct |
| 7 |
Correct |
2 ms |
304 KB |
Output is correct |
| 8 |
Correct |
3 ms |
384 KB |
Output is correct |
| 9 |
Correct |
3 ms |
256 KB |
Output is correct |
| 10 |
Correct |
3 ms |
256 KB |
Output is correct |
| 11 |
Correct |
2 ms |
256 KB |
Output is correct |
| 12 |
Correct |
2 ms |
256 KB |
Output is correct |
| 13 |
Correct |
3 ms |
256 KB |
Output is correct |
| 14 |
Correct |
3 ms |
384 KB |
Output is correct |
| 15 |
Correct |
3 ms |
128 KB |
Output is correct |
| 16 |
Correct |
3 ms |
384 KB |
Output is correct |
| 17 |
Correct |
3 ms |
256 KB |
Output is correct |
| 18 |
Correct |
2 ms |
256 KB |
Output is correct |
| 19 |
Correct |
2 ms |
256 KB |
Output is correct |
| 20 |
Correct |
2 ms |
256 KB |
Output is correct |
| 21 |
Correct |
3 ms |
384 KB |
Output is correct |
| 22 |
Correct |
3 ms |
384 KB |
Output is correct |
| 23 |
Correct |
3 ms |
304 KB |
Output is correct |
| 24 |
Correct |
3 ms |
384 KB |
Output is correct |
| 25 |
Correct |
2 ms |
256 KB |
Output is correct |
| 26 |
Correct |
3 ms |
384 KB |
Output is correct |
| 27 |
Correct |
3 ms |
384 KB |
Output is correct |
| 28 |
Correct |
3 ms |
384 KB |
Output is correct |
| 29 |
Correct |
3 ms |
256 KB |
Output is correct |
| 30 |
Correct |
2 ms |
384 KB |
Output is correct |
| 31 |
Correct |
18 ms |
1920 KB |
Output is correct |
| 32 |
Correct |
18 ms |
1920 KB |
Output is correct |
| 33 |
Correct |
18 ms |
1892 KB |
Output is correct |
| 34 |
Correct |
18 ms |
1920 KB |
Output is correct |
| 35 |
Correct |
23 ms |
1924 KB |
Output is correct |
| 36 |
Correct |
24 ms |
1920 KB |
Output is correct |
| 37 |
Correct |
25 ms |
1920 KB |
Output is correct |
| 38 |
Correct |
6 ms |
512 KB |
Output is correct |
| 39 |
Correct |
16 ms |
1408 KB |
Output is correct |
| 40 |
Correct |
22 ms |
1864 KB |
Output is correct |
