#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
using ll = long long;
const ll M = 1'000'000'007;
int n, l, a[100], dp[2][101][1001][3], z;
int main()
{
ShinLena;
cin >> n >> l;
for (int i = 0; i < n; ++i) cin >> a[i];
sort(a, a+n);
dp[1][1][0][0] = 1;
dp[1][1][0][1] = 1;
dp[1][1][0][2] = 1;
for (int i = 1, I = 0, D = a[1] - a[0]; i < n; ++i, I ^= 1, D = a[i] - a[i-1])
{
memset(dp[I], 0, sizeof *dp);
for (int j = 1; j <= 1 + i; ++j)
{
for (int k = 0; k <= l; ++k)
{
/* dp[I][j][k][0] */ {
if ((2*j+2) * D <= k) /* merge */
(dp[I][j][k][0] += (dp[!I][j+1][k - ((2*j+2) * D)][0] * j % M)) %= M;
if ((2*j-2) * D <= k) /* insert */
(dp[I][j][k][0] += (dp[!I][j-1][k - ((2*j-2) * D)][0] * j % M)) %= M;
if ((2*j+0) * D <= k) /* append */
(dp[I][j][k][0] += (dp[!I][j+0][k - ((2*j+0) * D)][0] * (2*j+0) % M)) %= M;
}
/* dp[I][j][k][1] */ {
if ((2*j+1) * D <= k) /* merge */
(dp[I][j][k][1] += (dp[!I][j+1][k - ((2*j+1) * D)][1] * j % M)) %= M;
if (j>1 && (2*j-3) * D <= k) /* non fixing insert */
(dp[I][j][k][1] += (dp[!I][j-1][k - ((2*j-3) * D)][1] * (j-1) % M)) %= M;
if ((2*j-1) * D <= k) /* non fixing append */
(dp[I][j][k][1] += (dp[!I][j+0][k - ((2*j-1) * D)][1] * (2*j-1) % M)) %= M;
if ((2*j-2) * D <= k) /* fixing insert */
(dp[I][j][k][1] += (dp[!I][j-1][k - ((2*j-2) * D)][0] * 2 % M)) %= M;
if ((2*j+0) * D <= k) /* fixing append */
(dp[I][j][k][1] += (dp[!I][j+0][k - ((2*j+0) * D)][0] * 2 % M)) %= M;
}
/* dp[I][j][k][2] */ {
if ((2*j+0) * D <= k) /* merge */
(dp[I][j][k][2] += (dp[!I][j+1][k - ((2*j) * D)][2] * j % M)) %= M;
if (j>1 && (2*j-4) * D <= k) /* non fixing insert */
(dp[I][j][k][2] += (dp[!I][j-1][k - ((2*j-4) * D)][2] * (j-2) % M)) %= M;
if ((2*j-2) * D <= k) /* non fixing append */
(dp[I][j][k][2] += (dp[!I][j+0][k - ((2*j-2) * D)][2] * (2*j-2) % M)) %= M;
if (j>1 && (2*j-3) * D <= k) /* fixing insert */
(dp[I][j][k][2] += (dp[!I][j-1][k - ((2*j-3) * D)][1] )) %= M;
if ((2*j-1) * D <= k) /* fixing append */
(dp[I][j][k][2] += (dp[!I][j+0][k - ((2*j-1) * D)][1] )) %= M;
}
}
}
}
for (int k = 0; k <= l; ++k) (z += dp[n&1][1][k][2] % M) %= M;
cout << z;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2396 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2396 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |