/**
* author: NimaAryan
* created: 2024-06-26 20:39:48
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#endif
using i64 = long long;
constexpr i64 mod = 1E9 + 7;
void add(i64& x, i64 y) {
if ((x += y) >= mod) {
x -= mod;
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int N, L;
cin >> N >> L;
vector<int> A(N);
for (int i = 0; i < N; ++i) {
cin >> A[i];
}
if (N == 1) {
cout << 1 << "\n";
return 0;
}
sort(A.begin(), A.end());
A.push_back(10000);
vector f(3, vector(N + 1, vector<i64>(L + 1)));
f[0][0][0] = 1;
for (int i = 0; i < N; ++i) {
vector g(3, vector(N + 1, vector<i64>(L + 1)));
for (int p = 0; p < 3; ++p) {
for (int c = 0; c <= N; ++c) {
for (int s = 0; s <= L; ++s) {
int d = A[i + 1] - A[i];
int new_s = s + (2 * c - p) * d;
{
if (c + 1 <= N && 0 <= new_s + 2 * d && new_s + 2 * d <= L) {
add(g[p][c + 1][new_s + 2 * d], f[p][c][s] * (c + 1 - p) % mod);
}
if (0 <= new_s && new_s <= L) {
add(g[p][c][new_s], f[p][c][s] * (2 * c - p) % mod);
}
if (c - 1 >= 1 && 0 <= new_s - 2 * d && new_s - 2 * d <= L) {
add(g[p][c - 1][new_s - 2 * d], f[p][c][s] * (c - 1) % mod);
}
}
if (p < 2) {
if (c + 1 <= N && 0 <= new_s + d && new_s + d <= L) {
add(g[p + 1][c + 1][new_s + d], f[p][c][s] * (2 - p) % mod);
}
if (0 <= new_s - d && new_s - d <= L) {
add(g[p + 1][c][new_s - d], f[p][c][s] * (2 - p) % mod);
}
}
}
}
}
f.swap(g);
}
i64 ans = 0;
for (int l = 0; l <= L; ++l) {
add(ans, f[2][1][l]);
}
cout << ans << "\n";
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
448 KB |
Output is correct |
5 |
Correct |
1 ms |
932 KB |
Output is correct |
6 |
Correct |
2 ms |
884 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
860 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
348 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
448 KB |
Output is correct |
5 |
Correct |
1 ms |
932 KB |
Output is correct |
6 |
Correct |
2 ms |
884 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
860 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
344 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
348 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
0 ms |
348 KB |
Output is correct |
18 |
Correct |
0 ms |
348 KB |
Output is correct |
19 |
Correct |
1 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Correct |
2 ms |
348 KB |
Output is correct |
22 |
Correct |
149 ms |
4112 KB |
Output is correct |
23 |
Correct |
176 ms |
5960 KB |
Output is correct |
24 |
Correct |
147 ms |
4580 KB |
Output is correct |
25 |
Correct |
182 ms |
5996 KB |
Output is correct |
26 |
Correct |
155 ms |
5184 KB |
Output is correct |
27 |
Correct |
52 ms |
1832 KB |
Output is correct |
28 |
Correct |
74 ms |
2136 KB |
Output is correct |
29 |
Correct |
135 ms |
3660 KB |
Output is correct |
30 |
Correct |
188 ms |
6016 KB |
Output is correct |