#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define all(x) (x).begin(),(x).end()
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define debug(x) cerr << #x << ": " << x << endl;
const ll MAXN = 1e5 + 10;
const ll MOD = 1e9 + 7;
inline ll poww(ll a, ll b) {
ll ans = 1;
while (b) {
if (b & 1) ans = ans * a % MOD;
a = a * a % MOD;
b >>= 1;
}
return ans;
}
ll fact[MAXN], inv[MAXN];
inline ll C(ll k, ll n) {
if (k < 0 || k > n) return 0;
return fact[n] * inv[k] % MOD * inv[n - k] % MOD;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
fact[0] = inv[0] = 1;
for (int i = 1; i < MAXN; i++) {
fact[i] = fact[i - 1] * i % MOD;
inv[i] = poww(fact[i], MOD - 2);
}
ll ans = 0;
ll n, k;
cin >> n >> k;
for (int i = 0; i <= k; i++) {
ans = (ans + MOD + (i & 1 ? -1 : 1) * C(i, n + 1) * poww(k - i, n) % MOD) % MOD;
}
cout << ans << endl;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
1876 KB |
Output is correct |
2 |
Correct |
14 ms |
1828 KB |
Output is correct |
3 |
Correct |
16 ms |
1768 KB |
Output is correct |
4 |
Correct |
15 ms |
1784 KB |
Output is correct |
5 |
Correct |
15 ms |
1876 KB |
Output is correct |
6 |
Correct |
15 ms |
1848 KB |
Output is correct |
7 |
Correct |
15 ms |
1800 KB |
Output is correct |
8 |
Correct |
15 ms |
1864 KB |
Output is correct |
9 |
Correct |
16 ms |
1876 KB |
Output is correct |
10 |
Correct |
15 ms |
1840 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
1876 KB |
Output is correct |
2 |
Correct |
14 ms |
1828 KB |
Output is correct |
3 |
Correct |
16 ms |
1768 KB |
Output is correct |
4 |
Correct |
15 ms |
1784 KB |
Output is correct |
5 |
Correct |
15 ms |
1876 KB |
Output is correct |
6 |
Correct |
15 ms |
1848 KB |
Output is correct |
7 |
Correct |
15 ms |
1800 KB |
Output is correct |
8 |
Correct |
15 ms |
1864 KB |
Output is correct |
9 |
Correct |
16 ms |
1876 KB |
Output is correct |
10 |
Correct |
15 ms |
1840 KB |
Output is correct |
11 |
Correct |
16 ms |
1832 KB |
Output is correct |
12 |
Correct |
15 ms |
1884 KB |
Output is correct |
13 |
Correct |
15 ms |
1796 KB |
Output is correct |
14 |
Correct |
16 ms |
1884 KB |
Output is correct |
15 |
Correct |
16 ms |
1776 KB |
Output is correct |
16 |
Correct |
15 ms |
1852 KB |
Output is correct |
17 |
Correct |
15 ms |
1876 KB |
Output is correct |
18 |
Correct |
15 ms |
1876 KB |
Output is correct |
19 |
Correct |
16 ms |
1792 KB |
Output is correct |
20 |
Correct |
15 ms |
1884 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
1876 KB |
Output is correct |
2 |
Correct |
14 ms |
1828 KB |
Output is correct |
3 |
Correct |
16 ms |
1768 KB |
Output is correct |
4 |
Correct |
15 ms |
1784 KB |
Output is correct |
5 |
Correct |
15 ms |
1876 KB |
Output is correct |
6 |
Correct |
15 ms |
1848 KB |
Output is correct |
7 |
Correct |
15 ms |
1800 KB |
Output is correct |
8 |
Correct |
15 ms |
1864 KB |
Output is correct |
9 |
Correct |
16 ms |
1876 KB |
Output is correct |
10 |
Correct |
15 ms |
1840 KB |
Output is correct |
11 |
Correct |
16 ms |
1832 KB |
Output is correct |
12 |
Correct |
15 ms |
1884 KB |
Output is correct |
13 |
Correct |
15 ms |
1796 KB |
Output is correct |
14 |
Correct |
16 ms |
1884 KB |
Output is correct |
15 |
Correct |
16 ms |
1776 KB |
Output is correct |
16 |
Correct |
15 ms |
1852 KB |
Output is correct |
17 |
Correct |
15 ms |
1876 KB |
Output is correct |
18 |
Correct |
15 ms |
1876 KB |
Output is correct |
19 |
Correct |
16 ms |
1792 KB |
Output is correct |
20 |
Correct |
15 ms |
1884 KB |
Output is correct |
21 |
Correct |
14 ms |
1780 KB |
Output is correct |
22 |
Correct |
15 ms |
1876 KB |
Output is correct |
23 |
Correct |
15 ms |
1788 KB |
Output is correct |
24 |
Correct |
16 ms |
2004 KB |
Output is correct |
25 |
Correct |
15 ms |
1876 KB |
Output is correct |
26 |
Correct |
14 ms |
1876 KB |
Output is correct |
27 |
Correct |
14 ms |
1812 KB |
Output is correct |
28 |
Correct |
14 ms |
1960 KB |
Output is correct |
29 |
Correct |
14 ms |
1876 KB |
Output is correct |
30 |
Correct |
14 ms |
1872 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
1876 KB |
Output is correct |
2 |
Correct |
14 ms |
1828 KB |
Output is correct |
3 |
Correct |
16 ms |
1768 KB |
Output is correct |
4 |
Correct |
15 ms |
1784 KB |
Output is correct |
5 |
Correct |
15 ms |
1876 KB |
Output is correct |
6 |
Correct |
15 ms |
1848 KB |
Output is correct |
7 |
Correct |
15 ms |
1800 KB |
Output is correct |
8 |
Correct |
15 ms |
1864 KB |
Output is correct |
9 |
Correct |
16 ms |
1876 KB |
Output is correct |
10 |
Correct |
15 ms |
1840 KB |
Output is correct |
11 |
Correct |
16 ms |
1832 KB |
Output is correct |
12 |
Correct |
15 ms |
1884 KB |
Output is correct |
13 |
Correct |
15 ms |
1796 KB |
Output is correct |
14 |
Correct |
16 ms |
1884 KB |
Output is correct |
15 |
Correct |
16 ms |
1776 KB |
Output is correct |
16 |
Correct |
15 ms |
1852 KB |
Output is correct |
17 |
Correct |
15 ms |
1876 KB |
Output is correct |
18 |
Correct |
15 ms |
1876 KB |
Output is correct |
19 |
Correct |
16 ms |
1792 KB |
Output is correct |
20 |
Correct |
15 ms |
1884 KB |
Output is correct |
21 |
Correct |
14 ms |
1780 KB |
Output is correct |
22 |
Correct |
15 ms |
1876 KB |
Output is correct |
23 |
Correct |
15 ms |
1788 KB |
Output is correct |
24 |
Correct |
16 ms |
2004 KB |
Output is correct |
25 |
Correct |
15 ms |
1876 KB |
Output is correct |
26 |
Correct |
14 ms |
1876 KB |
Output is correct |
27 |
Correct |
14 ms |
1812 KB |
Output is correct |
28 |
Correct |
14 ms |
1960 KB |
Output is correct |
29 |
Correct |
14 ms |
1876 KB |
Output is correct |
30 |
Correct |
14 ms |
1872 KB |
Output is correct |
31 |
Correct |
14 ms |
1876 KB |
Output is correct |
32 |
Correct |
14 ms |
1892 KB |
Output is correct |
33 |
Correct |
16 ms |
1876 KB |
Output is correct |
34 |
Correct |
16 ms |
1864 KB |
Output is correct |
35 |
Correct |
21 ms |
1888 KB |
Output is correct |
36 |
Correct |
22 ms |
1764 KB |
Output is correct |
37 |
Correct |
24 ms |
1876 KB |
Output is correct |
38 |
Correct |
16 ms |
1804 KB |
Output is correct |
39 |
Correct |
19 ms |
1768 KB |
Output is correct |
40 |
Correct |
19 ms |
1868 KB |
Output is correct |