#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9, MOD = 1e9 + 7;
int main() {
int N, L;
cin >> N >> L;
vector<int> A(N + 1);
for (int i = 1; i <= N; i++)
cin >> A[i];
sort(A.begin() + 1, A.end());
A.push_back(INF);
if (N == 1) {
cout << 1 << '\n';
return 0;
}
vector<vector<vector<array<long long, 3>>>> dp(N + 1, vector<vector<array<long long, 3>>>(N + 1, vector<array<long long, 3>>(L + 1)));
dp[0][0][0][0] = 1;
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= i; j++) {
for (int k = 0; k <= L; k++) {
for (int m = 0; m <= 2; m++) {
int d = (2 * j - m) * (A[i + 1] - A[i]);
if (d > k || i + j + 1 - m > N)
continue;
long long &f = dp[i][j][k][m];
f = 0;
f += dp[i - 1][j - 1][k - d][m];
f += m == 0 ? 0 : (3 - m) * dp[i - 1][j - 1][k - d][m - 1];
f += (2 * j - m) * dp[i - 1][j][k - d][m];
f += m == 0 ? 0 : (m == 1 ? 2 * j * dp[i - 1][j][k - d][m - 1] : (i == N ? dp[i - 1][j][k - d][m - 1] : (j - 1) * dp[i - 1][j][k - d][m - 1]));
f += m == 0 ? j * (j + 1) * dp[i - 1][j + 1][k - d][m] : (m == 1 ? j * j * dp[i - 1][j + 1][k - d][m] : (i == N ? dp[i - 1][j + 1][k - d][m] : j * (j - 1) * dp[i - 1][j + 1][k - d][m]));
f %= MOD;
}
}
}
}
long long ans = 0;
for (int k = 0; k <= L; k++)
ans += dp[N][1][k][2];
cout << ans % MOD << '\n';
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
1 ms |
212 KB |
Output is correct |
| 3 |
Correct |
1 ms |
212 KB |
Output is correct |
| 4 |
Correct |
1 ms |
420 KB |
Output is correct |
| 5 |
Correct |
2 ms |
2220 KB |
Output is correct |
| 6 |
Correct |
2 ms |
2088 KB |
Output is correct |
| 7 |
Correct |
1 ms |
596 KB |
Output is correct |
| 8 |
Correct |
1 ms |
468 KB |
Output is correct |
| 9 |
Correct |
2 ms |
2132 KB |
Output is correct |
| 10 |
Correct |
1 ms |
468 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
468 KB |
Output is correct |
| 2 |
Correct |
1 ms |
852 KB |
Output is correct |
| 3 |
Correct |
1 ms |
468 KB |
Output is correct |
| 4 |
Correct |
1 ms |
812 KB |
Output is correct |
| 5 |
Correct |
1 ms |
852 KB |
Output is correct |
| 6 |
Correct |
1 ms |
724 KB |
Output is correct |
| 7 |
Correct |
0 ms |
468 KB |
Output is correct |
| 8 |
Correct |
1 ms |
468 KB |
Output is correct |
| 9 |
Correct |
1 ms |
596 KB |
Output is correct |
| 10 |
Correct |
1 ms |
724 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
Output is correct |
| 2 |
Correct |
1 ms |
212 KB |
Output is correct |
| 3 |
Correct |
1 ms |
212 KB |
Output is correct |
| 4 |
Correct |
1 ms |
420 KB |
Output is correct |
| 5 |
Correct |
2 ms |
2220 KB |
Output is correct |
| 6 |
Correct |
2 ms |
2088 KB |
Output is correct |
| 7 |
Correct |
1 ms |
596 KB |
Output is correct |
| 8 |
Correct |
1 ms |
468 KB |
Output is correct |
| 9 |
Correct |
2 ms |
2132 KB |
Output is correct |
| 10 |
Correct |
1 ms |
468 KB |
Output is correct |
| 11 |
Correct |
1 ms |
468 KB |
Output is correct |
| 12 |
Correct |
1 ms |
852 KB |
Output is correct |
| 13 |
Correct |
1 ms |
468 KB |
Output is correct |
| 14 |
Correct |
1 ms |
812 KB |
Output is correct |
| 15 |
Correct |
1 ms |
852 KB |
Output is correct |
| 16 |
Correct |
1 ms |
724 KB |
Output is correct |
| 17 |
Correct |
0 ms |
468 KB |
Output is correct |
| 18 |
Correct |
1 ms |
468 KB |
Output is correct |
| 19 |
Correct |
1 ms |
596 KB |
Output is correct |
| 20 |
Correct |
1 ms |
724 KB |
Output is correct |
| 21 |
Correct |
2 ms |
1876 KB |
Output is correct |
| 22 |
Correct |
82 ms |
122648 KB |
Output is correct |
| 23 |
Correct |
139 ms |
238320 KB |
Output is correct |
| 24 |
Correct |
103 ms |
180300 KB |
Output is correct |
| 25 |
Correct |
139 ms |
241456 KB |
Output is correct |
| 26 |
Correct |
128 ms |
205320 KB |
Output is correct |
| 27 |
Correct |
37 ms |
59860 KB |
Output is correct |
| 28 |
Correct |
46 ms |
73344 KB |
Output is correct |
| 29 |
Correct |
84 ms |
139236 KB |
Output is correct |
| 30 |
Correct |
149 ms |
242540 KB |
Output is correct |
