#include <bits/stdc++.h>
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define bp __builtin_popcount
#define fir first
#define sec second
#define pii pair<int, int>
#define pll pair<ll, ll>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
using namespace std;
int dx[4]={0, 1, 0, -1}, dy[4]={1, 0, -1 , 0};
const int mxN=100010;
const int mxM=350;
const int mxK=350;
const ll MOD=1000000007;
const ll INF=100000000000001;
int N, K;
ll fact[mxN], ifact[mxN];
ll ans;
ll mypow(ll a, ll b)
{
if(b==0) return 1;
if(b==1) return a%MOD;
ll tmp=mypow(a, b/2);
tmp=(tmp*tmp)%MOD;
if(b%2) tmp=(a*tmp)%MOD;
return tmp;
}
int main()
{
gibon
cin >> N >> K; K--;
fact[0]=1; ifact[0]=1;
for(int i=1;i<=N+1;i++) fact[i]=(fact[i-1]*i)%MOD;
for(int i=1;i<=N+1;i++) ifact[i]=mypow(fact[i], MOD-2);
for(int i=0;i<=K;i++)
{
ll res=fact[N+1];
res*=ifact[i]; res%=MOD;
res*=ifact[N+1-i]; res%=MOD;
res*=mypow(K+1-i, N); res%=MOD;
if(i%2==0) ans=(ans+res)%MOD;
else ans=(ans+MOD-res)%MOD;
}
cout << ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
324 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
324 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
332 KB |
Output is correct |
14 |
Correct |
1 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
324 KB |
Output is correct |
16 |
Correct |
1 ms |
332 KB |
Output is correct |
17 |
Correct |
1 ms |
204 KB |
Output is correct |
18 |
Correct |
1 ms |
316 KB |
Output is correct |
19 |
Correct |
1 ms |
332 KB |
Output is correct |
20 |
Correct |
1 ms |
332 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
324 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
332 KB |
Output is correct |
14 |
Correct |
1 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
324 KB |
Output is correct |
16 |
Correct |
1 ms |
332 KB |
Output is correct |
17 |
Correct |
1 ms |
204 KB |
Output is correct |
18 |
Correct |
1 ms |
316 KB |
Output is correct |
19 |
Correct |
1 ms |
332 KB |
Output is correct |
20 |
Correct |
1 ms |
332 KB |
Output is correct |
21 |
Correct |
1 ms |
332 KB |
Output is correct |
22 |
Correct |
1 ms |
332 KB |
Output is correct |
23 |
Correct |
1 ms |
332 KB |
Output is correct |
24 |
Correct |
1 ms |
332 KB |
Output is correct |
25 |
Correct |
1 ms |
332 KB |
Output is correct |
26 |
Correct |
1 ms |
332 KB |
Output is correct |
27 |
Correct |
1 ms |
336 KB |
Output is correct |
28 |
Correct |
1 ms |
332 KB |
Output is correct |
29 |
Correct |
1 ms |
204 KB |
Output is correct |
30 |
Correct |
1 ms |
332 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
204 KB |
Output is correct |
2 |
Correct |
1 ms |
204 KB |
Output is correct |
3 |
Correct |
1 ms |
332 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
1 ms |
204 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
324 KB |
Output is correct |
11 |
Correct |
1 ms |
204 KB |
Output is correct |
12 |
Correct |
1 ms |
316 KB |
Output is correct |
13 |
Correct |
1 ms |
332 KB |
Output is correct |
14 |
Correct |
1 ms |
332 KB |
Output is correct |
15 |
Correct |
1 ms |
324 KB |
Output is correct |
16 |
Correct |
1 ms |
332 KB |
Output is correct |
17 |
Correct |
1 ms |
204 KB |
Output is correct |
18 |
Correct |
1 ms |
316 KB |
Output is correct |
19 |
Correct |
1 ms |
332 KB |
Output is correct |
20 |
Correct |
1 ms |
332 KB |
Output is correct |
21 |
Correct |
1 ms |
332 KB |
Output is correct |
22 |
Correct |
1 ms |
332 KB |
Output is correct |
23 |
Correct |
1 ms |
332 KB |
Output is correct |
24 |
Correct |
1 ms |
332 KB |
Output is correct |
25 |
Correct |
1 ms |
332 KB |
Output is correct |
26 |
Correct |
1 ms |
332 KB |
Output is correct |
27 |
Correct |
1 ms |
336 KB |
Output is correct |
28 |
Correct |
1 ms |
332 KB |
Output is correct |
29 |
Correct |
1 ms |
204 KB |
Output is correct |
30 |
Correct |
1 ms |
332 KB |
Output is correct |
31 |
Correct |
26 ms |
1848 KB |
Output is correct |
32 |
Correct |
26 ms |
1824 KB |
Output is correct |
33 |
Correct |
27 ms |
1848 KB |
Output is correct |
34 |
Correct |
28 ms |
1968 KB |
Output is correct |
35 |
Correct |
38 ms |
1868 KB |
Output is correct |
36 |
Correct |
39 ms |
1872 KB |
Output is correct |
37 |
Correct |
40 ms |
1792 KB |
Output is correct |
38 |
Correct |
7 ms |
568 KB |
Output is correct |
39 |
Correct |
24 ms |
1404 KB |
Output is correct |
40 |
Correct |
32 ms |
1816 KB |
Output is correct |