oj.uz

Submission #1047221

# Submission time Handle Problem Language Result Execution time Memory
1047221 2024-08-07T10:58:54 Z nima_aryan Skyscraper (JOI16_skyscraper) C++17
100 / 100
 188 ms 6016 KB 
/**
 *    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;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory 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

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory 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

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory 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