#include <bits/stdc++.h>
#define ff first
#define ss second
#define endl '\n'
using namespace std;
const long long INF = (long long) 1e18;
const int mod = (int) 1e9+7;
const int MAXN = (int) 1e5+5;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
int n, k;
int dp[MAXN];
ll fact[MAXN];
ll inv[MAXN];
ll bp(ll a, ll b){
ll res = 1;
while(b){
if(b % 2) res = (res * a) % mod;
a = (a * a) % mod;
b = b / 2;
}
return res;
}
ll comb(ll a, ll b){
return fact[a]*inv[b]%mod*inv[a - b]%mod;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);cout.tie(nullptr);
#ifdef Local
freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/int.txt","r",stdin);
freopen("C:/Users/Admin/Desktop/Yazilim/C/IO/out.txt","w",stdout);
#endif
cin>>n>>k;
fact[0] = 1;
inv[0] = 1;
for(int i = 1; i <= n + 10; i++){
fact[i] = fact[i - 1]* i % mod;
inv[i] = bp(fact[i], mod - 2);
}
ll ans = 0;
for(int i = 0; i < k; i++){
ans += (i % 2 ? -1: 1)*(comb(n + 1, i)*bp((k - i), n)%mod);
ans += mod;
ans %= mod;
}
cout<<ans<<endl;
#ifdef Local
cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
#endif
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
380 KB |
Output is correct |
2 |
Correct |
5 ms |
376 KB |
Output is correct |
3 |
Correct |
5 ms |
376 KB |
Output is correct |
4 |
Correct |
5 ms |
376 KB |
Output is correct |
5 |
Correct |
5 ms |
376 KB |
Output is correct |
6 |
Correct |
5 ms |
376 KB |
Output is correct |
7 |
Correct |
5 ms |
376 KB |
Output is correct |
8 |
Correct |
5 ms |
376 KB |
Output is correct |
9 |
Correct |
5 ms |
376 KB |
Output is correct |
10 |
Correct |
5 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
380 KB |
Output is correct |
2 |
Correct |
5 ms |
376 KB |
Output is correct |
3 |
Correct |
5 ms |
376 KB |
Output is correct |
4 |
Correct |
5 ms |
376 KB |
Output is correct |
5 |
Correct |
5 ms |
376 KB |
Output is correct |
6 |
Correct |
5 ms |
376 KB |
Output is correct |
7 |
Correct |
5 ms |
376 KB |
Output is correct |
8 |
Correct |
5 ms |
376 KB |
Output is correct |
9 |
Correct |
5 ms |
376 KB |
Output is correct |
10 |
Correct |
5 ms |
376 KB |
Output is correct |
11 |
Correct |
5 ms |
376 KB |
Output is correct |
12 |
Correct |
5 ms |
376 KB |
Output is correct |
13 |
Correct |
5 ms |
376 KB |
Output is correct |
14 |
Correct |
5 ms |
376 KB |
Output is correct |
15 |
Correct |
5 ms |
376 KB |
Output is correct |
16 |
Correct |
5 ms |
376 KB |
Output is correct |
17 |
Correct |
5 ms |
504 KB |
Output is correct |
18 |
Correct |
5 ms |
380 KB |
Output is correct |
19 |
Correct |
5 ms |
376 KB |
Output is correct |
20 |
Correct |
5 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
380 KB |
Output is correct |
2 |
Correct |
5 ms |
376 KB |
Output is correct |
3 |
Correct |
5 ms |
376 KB |
Output is correct |
4 |
Correct |
5 ms |
376 KB |
Output is correct |
5 |
Correct |
5 ms |
376 KB |
Output is correct |
6 |
Correct |
5 ms |
376 KB |
Output is correct |
7 |
Correct |
5 ms |
376 KB |
Output is correct |
8 |
Correct |
5 ms |
376 KB |
Output is correct |
9 |
Correct |
5 ms |
376 KB |
Output is correct |
10 |
Correct |
5 ms |
376 KB |
Output is correct |
11 |
Correct |
5 ms |
376 KB |
Output is correct |
12 |
Correct |
5 ms |
376 KB |
Output is correct |
13 |
Correct |
5 ms |
376 KB |
Output is correct |
14 |
Correct |
5 ms |
376 KB |
Output is correct |
15 |
Correct |
5 ms |
376 KB |
Output is correct |
16 |
Correct |
5 ms |
376 KB |
Output is correct |
17 |
Correct |
5 ms |
504 KB |
Output is correct |
18 |
Correct |
5 ms |
380 KB |
Output is correct |
19 |
Correct |
5 ms |
376 KB |
Output is correct |
20 |
Correct |
5 ms |
376 KB |
Output is correct |
21 |
Correct |
5 ms |
376 KB |
Output is correct |
22 |
Correct |
6 ms |
376 KB |
Output is correct |
23 |
Correct |
5 ms |
376 KB |
Output is correct |
24 |
Correct |
5 ms |
376 KB |
Output is correct |
25 |
Correct |
5 ms |
376 KB |
Output is correct |
26 |
Correct |
5 ms |
376 KB |
Output is correct |
27 |
Correct |
5 ms |
376 KB |
Output is correct |
28 |
Correct |
5 ms |
376 KB |
Output is correct |
29 |
Correct |
5 ms |
376 KB |
Output is correct |
30 |
Correct |
5 ms |
376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
380 KB |
Output is correct |
2 |
Correct |
5 ms |
376 KB |
Output is correct |
3 |
Correct |
5 ms |
376 KB |
Output is correct |
4 |
Correct |
5 ms |
376 KB |
Output is correct |
5 |
Correct |
5 ms |
376 KB |
Output is correct |
6 |
Correct |
5 ms |
376 KB |
Output is correct |
7 |
Correct |
5 ms |
376 KB |
Output is correct |
8 |
Correct |
5 ms |
376 KB |
Output is correct |
9 |
Correct |
5 ms |
376 KB |
Output is correct |
10 |
Correct |
5 ms |
376 KB |
Output is correct |
11 |
Correct |
5 ms |
376 KB |
Output is correct |
12 |
Correct |
5 ms |
376 KB |
Output is correct |
13 |
Correct |
5 ms |
376 KB |
Output is correct |
14 |
Correct |
5 ms |
376 KB |
Output is correct |
15 |
Correct |
5 ms |
376 KB |
Output is correct |
16 |
Correct |
5 ms |
376 KB |
Output is correct |
17 |
Correct |
5 ms |
504 KB |
Output is correct |
18 |
Correct |
5 ms |
380 KB |
Output is correct |
19 |
Correct |
5 ms |
376 KB |
Output is correct |
20 |
Correct |
5 ms |
376 KB |
Output is correct |
21 |
Correct |
5 ms |
376 KB |
Output is correct |
22 |
Correct |
6 ms |
376 KB |
Output is correct |
23 |
Correct |
5 ms |
376 KB |
Output is correct |
24 |
Correct |
5 ms |
376 KB |
Output is correct |
25 |
Correct |
5 ms |
376 KB |
Output is correct |
26 |
Correct |
5 ms |
376 KB |
Output is correct |
27 |
Correct |
5 ms |
376 KB |
Output is correct |
28 |
Correct |
5 ms |
376 KB |
Output is correct |
29 |
Correct |
5 ms |
376 KB |
Output is correct |
30 |
Correct |
5 ms |
376 KB |
Output is correct |
31 |
Correct |
22 ms |
1912 KB |
Output is correct |
32 |
Correct |
21 ms |
1912 KB |
Output is correct |
33 |
Correct |
22 ms |
2040 KB |
Output is correct |
34 |
Correct |
22 ms |
2040 KB |
Output is correct |
35 |
Correct |
29 ms |
1912 KB |
Output is correct |
36 |
Correct |
29 ms |
1912 KB |
Output is correct |
37 |
Correct |
31 ms |
1912 KB |
Output is correct |
38 |
Correct |
8 ms |
632 KB |
Output is correct |
39 |
Correct |
19 ms |
1400 KB |
Output is correct |
40 |
Correct |
24 ms |
1912 KB |
Output is correct |