#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
int add(int a,int b) {
a += b;
if(a >= mod)a -= mod;
return a;
}
int sub(int a,int b) {
a -= b;
if(a < 0) a += mod;
return a;
}
int mul(int a,int b) {
return 1ll * a * b % mod;
}
int Pow(int a,int b) {
int ans = 1;
for(; b ; b >>= 1, a = mul(a,a)) if (b & 1)
ans = mul(ans, a);
return ans;
}
int Fac[N];
int Inv[N];
int Ckn(int n,int k) {
if (n < k) return 0;
if (k < 0) return 0;
return mul(Fac[n],mul(Inv[k],Inv[n - k]));
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n; cin >> n;
int k; cin >> k;
Fac[0] = Inv[0] = 1;
for(int i = 1 ; i < N ; ++i) Fac[i] = mul(Fac[i - 1],i); Inv[N - 1] = Pow(Fac[N - 1],mod - 2);
for(int i = N - 2 ; i ; --i) Inv[i] = mul(Inv[i + 1],i + 1);
int ans = 0;
for(int i = 0 ; i < k ; ++i) {
int cur = mul(Ckn(n + 1,i),Pow(k - i,n));
if (i & 1) ans = sub(ans,cur);
else ans = add(ans,cur);
}
cout << ans << endl;
}
Compilation message
asceticism.cpp: In function 'int main()':
asceticism.cpp:48:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
for(int i = 1 ; i < N ; ++i) Fac[i] = mul(Fac[i - 1],i); Inv[N - 1] = Pow(Fac[N - 1],mod - 2);
^~~
asceticism.cpp:48:65: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
for(int i = 1 ; i < N ; ++i) Fac[i] = mul(Fac[i - 1],i); Inv[N - 1] = Pow(Fac[N - 1],mod - 2);
^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
1144 KB |
Output is correct |
2 |
Correct |
4 ms |
1144 KB |
Output is correct |
3 |
Correct |
4 ms |
1144 KB |
Output is correct |
4 |
Correct |
4 ms |
1144 KB |
Output is correct |
5 |
Correct |
4 ms |
1144 KB |
Output is correct |
6 |
Correct |
4 ms |
1144 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1144 KB |
Output is correct |
9 |
Correct |
4 ms |
1144 KB |
Output is correct |
10 |
Correct |
4 ms |
1144 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
1144 KB |
Output is correct |
2 |
Correct |
4 ms |
1144 KB |
Output is correct |
3 |
Correct |
4 ms |
1144 KB |
Output is correct |
4 |
Correct |
4 ms |
1144 KB |
Output is correct |
5 |
Correct |
4 ms |
1144 KB |
Output is correct |
6 |
Correct |
4 ms |
1144 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1144 KB |
Output is correct |
9 |
Correct |
4 ms |
1144 KB |
Output is correct |
10 |
Correct |
4 ms |
1144 KB |
Output is correct |
11 |
Correct |
4 ms |
1144 KB |
Output is correct |
12 |
Correct |
4 ms |
1144 KB |
Output is correct |
13 |
Correct |
4 ms |
1144 KB |
Output is correct |
14 |
Correct |
4 ms |
1144 KB |
Output is correct |
15 |
Correct |
4 ms |
1144 KB |
Output is correct |
16 |
Correct |
4 ms |
1144 KB |
Output is correct |
17 |
Correct |
4 ms |
1144 KB |
Output is correct |
18 |
Correct |
4 ms |
1144 KB |
Output is correct |
19 |
Correct |
4 ms |
1144 KB |
Output is correct |
20 |
Correct |
4 ms |
1144 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
1144 KB |
Output is correct |
2 |
Correct |
4 ms |
1144 KB |
Output is correct |
3 |
Correct |
4 ms |
1144 KB |
Output is correct |
4 |
Correct |
4 ms |
1144 KB |
Output is correct |
5 |
Correct |
4 ms |
1144 KB |
Output is correct |
6 |
Correct |
4 ms |
1144 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1144 KB |
Output is correct |
9 |
Correct |
4 ms |
1144 KB |
Output is correct |
10 |
Correct |
4 ms |
1144 KB |
Output is correct |
11 |
Correct |
4 ms |
1144 KB |
Output is correct |
12 |
Correct |
4 ms |
1144 KB |
Output is correct |
13 |
Correct |
4 ms |
1144 KB |
Output is correct |
14 |
Correct |
4 ms |
1144 KB |
Output is correct |
15 |
Correct |
4 ms |
1144 KB |
Output is correct |
16 |
Correct |
4 ms |
1144 KB |
Output is correct |
17 |
Correct |
4 ms |
1144 KB |
Output is correct |
18 |
Correct |
4 ms |
1144 KB |
Output is correct |
19 |
Correct |
4 ms |
1144 KB |
Output is correct |
20 |
Correct |
4 ms |
1144 KB |
Output is correct |
21 |
Correct |
4 ms |
1056 KB |
Output is correct |
22 |
Correct |
4 ms |
1144 KB |
Output is correct |
23 |
Correct |
4 ms |
1144 KB |
Output is correct |
24 |
Correct |
4 ms |
1144 KB |
Output is correct |
25 |
Correct |
4 ms |
1272 KB |
Output is correct |
26 |
Correct |
4 ms |
1144 KB |
Output is correct |
27 |
Correct |
4 ms |
1144 KB |
Output is correct |
28 |
Correct |
4 ms |
1144 KB |
Output is correct |
29 |
Correct |
4 ms |
1144 KB |
Output is correct |
30 |
Correct |
4 ms |
1144 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
1144 KB |
Output is correct |
2 |
Correct |
4 ms |
1144 KB |
Output is correct |
3 |
Correct |
4 ms |
1144 KB |
Output is correct |
4 |
Correct |
4 ms |
1144 KB |
Output is correct |
5 |
Correct |
4 ms |
1144 KB |
Output is correct |
6 |
Correct |
4 ms |
1144 KB |
Output is correct |
7 |
Correct |
4 ms |
1016 KB |
Output is correct |
8 |
Correct |
4 ms |
1144 KB |
Output is correct |
9 |
Correct |
4 ms |
1144 KB |
Output is correct |
10 |
Correct |
4 ms |
1144 KB |
Output is correct |
11 |
Correct |
4 ms |
1144 KB |
Output is correct |
12 |
Correct |
4 ms |
1144 KB |
Output is correct |
13 |
Correct |
4 ms |
1144 KB |
Output is correct |
14 |
Correct |
4 ms |
1144 KB |
Output is correct |
15 |
Correct |
4 ms |
1144 KB |
Output is correct |
16 |
Correct |
4 ms |
1144 KB |
Output is correct |
17 |
Correct |
4 ms |
1144 KB |
Output is correct |
18 |
Correct |
4 ms |
1144 KB |
Output is correct |
19 |
Correct |
4 ms |
1144 KB |
Output is correct |
20 |
Correct |
4 ms |
1144 KB |
Output is correct |
21 |
Correct |
4 ms |
1056 KB |
Output is correct |
22 |
Correct |
4 ms |
1144 KB |
Output is correct |
23 |
Correct |
4 ms |
1144 KB |
Output is correct |
24 |
Correct |
4 ms |
1144 KB |
Output is correct |
25 |
Correct |
4 ms |
1272 KB |
Output is correct |
26 |
Correct |
4 ms |
1144 KB |
Output is correct |
27 |
Correct |
4 ms |
1144 KB |
Output is correct |
28 |
Correct |
4 ms |
1144 KB |
Output is correct |
29 |
Correct |
4 ms |
1144 KB |
Output is correct |
30 |
Correct |
4 ms |
1144 KB |
Output is correct |
31 |
Correct |
4 ms |
1144 KB |
Output is correct |
32 |
Correct |
4 ms |
1144 KB |
Output is correct |
33 |
Correct |
5 ms |
1148 KB |
Output is correct |
34 |
Correct |
5 ms |
1144 KB |
Output is correct |
35 |
Correct |
12 ms |
1144 KB |
Output is correct |
36 |
Correct |
13 ms |
1144 KB |
Output is correct |
37 |
Correct |
14 ms |
1144 KB |
Output is correct |
38 |
Correct |
5 ms |
1144 KB |
Output is correct |
39 |
Correct |
7 ms |
1144 KB |
Output is correct |
40 |
Correct |
8 ms |
1144 KB |
Output is correct |