#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
#define pb push_back
#define f first
#define s second
const int MAXN = 1e5 + 10;
const ll MOD = 1e9 + 7;
ll fact[MAXN];
ll iFact[MAXN];
ll comb(int n, int k) {
return fact[n] * iFact[k] % MOD * iFact[n - k] % MOD;
}
ll binExp(ll base, int exp) {
base %= MOD;
ll prod = 1;
while (exp > 0) {
if (exp & 1) {
prod = prod * base % MOD;
}
base = base * base % MOD;
exp >>= 1;
}
return prod;
}
int main() {
fact[0] = 1;
for (int i = 1; i < MAXN; i++) {
fact[i] = fact[i - 1] * i % MOD;
}
iFact[MAXN - 1] = 549915853;
assert(fact[MAXN - 1] * iFact[MAXN - 1] % MOD == 1);
for (int i = MAXN - 2; i >= 0; i--) {
iFact[i] = (i + 1) * iFact[i + 1] % MOD;
assert(fact[i] * iFact[i] % MOD == 1);
}
// cout << comb(23134, 242) << endl;
// cout << binExp(2342, 124515) << endl;
int N, K;
cin >> N >> K;
K--;
ll sum = 0;
for (int i = 0; i <= K; i++) {
ll val = comb(N + 1, i) * binExp(K + 1 - i, N) % MOD;
// cout << val << endl;
if (i % 2 == 0) {
sum = (sum + val) % MOD;
} else {
sum = (sum - val + MOD) % MOD;
}
}
cout << sum << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1912 KB |
Output is correct |
2 |
Correct |
7 ms |
1784 KB |
Output is correct |
3 |
Correct |
7 ms |
1912 KB |
Output is correct |
4 |
Correct |
7 ms |
1912 KB |
Output is correct |
5 |
Correct |
7 ms |
1912 KB |
Output is correct |
6 |
Correct |
8 ms |
1912 KB |
Output is correct |
7 |
Correct |
7 ms |
1912 KB |
Output is correct |
8 |
Correct |
7 ms |
1912 KB |
Output is correct |
9 |
Correct |
7 ms |
1912 KB |
Output is correct |
10 |
Correct |
7 ms |
1912 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1912 KB |
Output is correct |
2 |
Correct |
7 ms |
1784 KB |
Output is correct |
3 |
Correct |
7 ms |
1912 KB |
Output is correct |
4 |
Correct |
7 ms |
1912 KB |
Output is correct |
5 |
Correct |
7 ms |
1912 KB |
Output is correct |
6 |
Correct |
8 ms |
1912 KB |
Output is correct |
7 |
Correct |
7 ms |
1912 KB |
Output is correct |
8 |
Correct |
7 ms |
1912 KB |
Output is correct |
9 |
Correct |
7 ms |
1912 KB |
Output is correct |
10 |
Correct |
7 ms |
1912 KB |
Output is correct |
11 |
Correct |
8 ms |
1912 KB |
Output is correct |
12 |
Correct |
7 ms |
1912 KB |
Output is correct |
13 |
Correct |
7 ms |
1916 KB |
Output is correct |
14 |
Correct |
7 ms |
1912 KB |
Output is correct |
15 |
Correct |
7 ms |
1912 KB |
Output is correct |
16 |
Correct |
7 ms |
1912 KB |
Output is correct |
17 |
Correct |
7 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1912 KB |
Output is correct |
19 |
Correct |
7 ms |
1912 KB |
Output is correct |
20 |
Correct |
7 ms |
1912 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1912 KB |
Output is correct |
2 |
Correct |
7 ms |
1784 KB |
Output is correct |
3 |
Correct |
7 ms |
1912 KB |
Output is correct |
4 |
Correct |
7 ms |
1912 KB |
Output is correct |
5 |
Correct |
7 ms |
1912 KB |
Output is correct |
6 |
Correct |
8 ms |
1912 KB |
Output is correct |
7 |
Correct |
7 ms |
1912 KB |
Output is correct |
8 |
Correct |
7 ms |
1912 KB |
Output is correct |
9 |
Correct |
7 ms |
1912 KB |
Output is correct |
10 |
Correct |
7 ms |
1912 KB |
Output is correct |
11 |
Correct |
8 ms |
1912 KB |
Output is correct |
12 |
Correct |
7 ms |
1912 KB |
Output is correct |
13 |
Correct |
7 ms |
1916 KB |
Output is correct |
14 |
Correct |
7 ms |
1912 KB |
Output is correct |
15 |
Correct |
7 ms |
1912 KB |
Output is correct |
16 |
Correct |
7 ms |
1912 KB |
Output is correct |
17 |
Correct |
7 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1912 KB |
Output is correct |
19 |
Correct |
7 ms |
1912 KB |
Output is correct |
20 |
Correct |
7 ms |
1912 KB |
Output is correct |
21 |
Correct |
7 ms |
1912 KB |
Output is correct |
22 |
Correct |
7 ms |
1912 KB |
Output is correct |
23 |
Correct |
7 ms |
1828 KB |
Output is correct |
24 |
Correct |
7 ms |
1908 KB |
Output is correct |
25 |
Correct |
7 ms |
1912 KB |
Output is correct |
26 |
Correct |
7 ms |
1912 KB |
Output is correct |
27 |
Correct |
7 ms |
1912 KB |
Output is correct |
28 |
Correct |
7 ms |
1912 KB |
Output is correct |
29 |
Correct |
7 ms |
1912 KB |
Output is correct |
30 |
Correct |
7 ms |
1912 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
1912 KB |
Output is correct |
2 |
Correct |
7 ms |
1784 KB |
Output is correct |
3 |
Correct |
7 ms |
1912 KB |
Output is correct |
4 |
Correct |
7 ms |
1912 KB |
Output is correct |
5 |
Correct |
7 ms |
1912 KB |
Output is correct |
6 |
Correct |
8 ms |
1912 KB |
Output is correct |
7 |
Correct |
7 ms |
1912 KB |
Output is correct |
8 |
Correct |
7 ms |
1912 KB |
Output is correct |
9 |
Correct |
7 ms |
1912 KB |
Output is correct |
10 |
Correct |
7 ms |
1912 KB |
Output is correct |
11 |
Correct |
8 ms |
1912 KB |
Output is correct |
12 |
Correct |
7 ms |
1912 KB |
Output is correct |
13 |
Correct |
7 ms |
1916 KB |
Output is correct |
14 |
Correct |
7 ms |
1912 KB |
Output is correct |
15 |
Correct |
7 ms |
1912 KB |
Output is correct |
16 |
Correct |
7 ms |
1912 KB |
Output is correct |
17 |
Correct |
7 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1912 KB |
Output is correct |
19 |
Correct |
7 ms |
1912 KB |
Output is correct |
20 |
Correct |
7 ms |
1912 KB |
Output is correct |
21 |
Correct |
7 ms |
1912 KB |
Output is correct |
22 |
Correct |
7 ms |
1912 KB |
Output is correct |
23 |
Correct |
7 ms |
1828 KB |
Output is correct |
24 |
Correct |
7 ms |
1908 KB |
Output is correct |
25 |
Correct |
7 ms |
1912 KB |
Output is correct |
26 |
Correct |
7 ms |
1912 KB |
Output is correct |
27 |
Correct |
7 ms |
1912 KB |
Output is correct |
28 |
Correct |
7 ms |
1912 KB |
Output is correct |
29 |
Correct |
7 ms |
1912 KB |
Output is correct |
30 |
Correct |
7 ms |
1912 KB |
Output is correct |
31 |
Correct |
7 ms |
1916 KB |
Output is correct |
32 |
Correct |
7 ms |
1912 KB |
Output is correct |
33 |
Correct |
7 ms |
1912 KB |
Output is correct |
34 |
Correct |
9 ms |
1928 KB |
Output is correct |
35 |
Correct |
14 ms |
1912 KB |
Output is correct |
36 |
Correct |
15 ms |
1912 KB |
Output is correct |
37 |
Correct |
16 ms |
1912 KB |
Output is correct |
38 |
Correct |
8 ms |
1912 KB |
Output is correct |
39 |
Correct |
10 ms |
1912 KB |
Output is correct |
40 |
Correct |
11 ms |
1912 KB |
Output is correct |