#include <bits/stdc++.h>
using namespace std;
const long long N = 1e4 + 5, mod = 1e9 + 7;
long long fac[N], inv[N];
long long n, l;
long long fp(long long base, long long power)
{
long long ret = 1;
while (power)
{
if (power & 1)
ret = (ret * base) % mod;
power >>= 1;
base = (base * base) % mod;
}
return ret;
}
long long ncr(long long nn, long long rr)
{
if (rr > nn || rr < 0)
return 0;
return ((fac[nn] * inv[rr]) % mod * inv[nn - rr]) % mod;
}
int main()
{
ios_base::sync_with_stdio(0), cin.tie(NULL), cout.tie(NULL);
cin >> n >> l;
vector<long long> arr(n);
for (int i = 0; i < n; i++)
cin >> arr[i];
fac[0] = fac[1] = 1;
for (long long i = 2; i <= l; i++)
fac[i] = (i * fac[i - 1]) % mod;
inv[l] = fp(fac[l], mod - 2);
for (long long i = l - 1; i >= 0; i--)
inv[i] = (inv[i + 1] * (i + 1)) % mod;
int boxes = l - (1 + arr[0] * (n - 1));
cout << (ncr(n + boxes, boxes) * fac[n]) % mod << "\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
604 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
604 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
604 KB |
Output is correct |
7 |
Correct |
0 ms |
460 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
600 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
604 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
604 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
604 KB |
Output is correct |
7 |
Correct |
0 ms |
460 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Incorrect |
0 ms |
600 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |