#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double ld;
#define pb push_back
#define sz(x) int32_t(x.size())
#define all(x) x.begin(),x.end()
#define F first
#define S second
#define int long long
const int N = 51, M = 1e9+7, L = 4e4;
int n, l;
pair<int, int> r[N];
ll fact[L+52], ncr[L+1][N+1];
ll fp(ll b, ll p) {
ll ret = 1;
while (p) {
if ((p & 1))ret = (ret * b) % M;
b = (b * b) % M;
p >>= 1;
}
return ret;
}
ll nCr(int a, int b) {
if (a < 0 || b > a)return 0;
return ncr[a][b];
}
signed main () {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n >> l;
fact[0] = 1;
for (ll i = 1; i <= L+50; i++) {
fact[i] = (fact[i-1] * i) % M;
}
ncr[0][0] = 1;
for (int i = 1; i <= L; i++) {
for (int j = 0; j <= min(n, i); j++) {
if (!j || j == i) {
ncr[i][j] = 1;
continue;
}
ncr[i][j] = (ncr[i-1][j] + ncr[i-1][j-1]) % M;
}
}
for (int i = 0; i < n; i++) {
cin >> r[i].F;
r[i].S = i;
}
sort(r, r+n);
if (r[0].F == r[n-1].F) {
cout << (fact[n] * nCr(l - (n-1)*r[0].F + n - 1, n))%M << "\n";
return 0;
}
if (n <= 10) {
ll ans = 0;
do {
int len = 1;
for (int i = 1; i < n; i++) {
len += max(r[i].F, r[i-1].F);
}
ans = (ans + nCr(l - len + n, n)) % M;
} while(next_permutation(r, r+n));
cout << ans << "\n";
return 0;
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
16988 KB |
Output is correct |
2 |
Correct |
5 ms |
17032 KB |
Output is correct |
3 |
Correct |
3 ms |
16988 KB |
Output is correct |
4 |
Correct |
3 ms |
16988 KB |
Output is correct |
5 |
Correct |
4 ms |
17028 KB |
Output is correct |
6 |
Correct |
5 ms |
17096 KB |
Output is correct |
7 |
Correct |
5 ms |
16988 KB |
Output is correct |
8 |
Correct |
3 ms |
16988 KB |
Output is correct |
9 |
Correct |
4 ms |
16848 KB |
Output is correct |
10 |
Correct |
2 ms |
16984 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
40 ms |
16988 KB |
Output is correct |
2 |
Correct |
3 ms |
16988 KB |
Output is correct |
3 |
Correct |
41 ms |
17040 KB |
Output is correct |
4 |
Correct |
3 ms |
16984 KB |
Output is correct |
5 |
Correct |
36 ms |
16988 KB |
Output is correct |
6 |
Correct |
3 ms |
16988 KB |
Output is correct |
7 |
Correct |
36 ms |
17052 KB |
Output is correct |
8 |
Correct |
35 ms |
17028 KB |
Output is correct |
9 |
Correct |
3 ms |
16984 KB |
Output is correct |
10 |
Correct |
3 ms |
16984 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
4 ms |
16988 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
16988 KB |
Output is correct |
2 |
Correct |
5 ms |
17032 KB |
Output is correct |
3 |
Correct |
3 ms |
16988 KB |
Output is correct |
4 |
Correct |
3 ms |
16988 KB |
Output is correct |
5 |
Correct |
4 ms |
17028 KB |
Output is correct |
6 |
Correct |
5 ms |
17096 KB |
Output is correct |
7 |
Correct |
5 ms |
16988 KB |
Output is correct |
8 |
Correct |
3 ms |
16988 KB |
Output is correct |
9 |
Correct |
4 ms |
16848 KB |
Output is correct |
10 |
Correct |
2 ms |
16984 KB |
Output is correct |
11 |
Correct |
40 ms |
16988 KB |
Output is correct |
12 |
Correct |
3 ms |
16988 KB |
Output is correct |
13 |
Correct |
41 ms |
17040 KB |
Output is correct |
14 |
Correct |
3 ms |
16984 KB |
Output is correct |
15 |
Correct |
36 ms |
16988 KB |
Output is correct |
16 |
Correct |
3 ms |
16988 KB |
Output is correct |
17 |
Correct |
36 ms |
17052 KB |
Output is correct |
18 |
Correct |
35 ms |
17028 KB |
Output is correct |
19 |
Correct |
3 ms |
16984 KB |
Output is correct |
20 |
Correct |
3 ms |
16984 KB |
Output is correct |
21 |
Incorrect |
4 ms |
16988 KB |
Output isn't correct |
22 |
Halted |
0 ms |
0 KB |
- |