oj.uz

Submission #1047249

# Submission time Handle Problem Language Result Execution time Memory
1047249 2024-08-07T11:19:16 Z nima_aryan Skyscraper (JOI16_skyscraper) C++17
100 / 100
 21 ms 6044 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;

inline 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(1, vector<i64>(L + 1)));
  f[0][0][0] = 1;
  for (int i = 0; i < N; ++i) {
    vector g(3, vector(i + 2, vector<i64>(L + 1)));
    for (int p = 0; p < 3; ++p) {
      for (int c = 0; c <= i; ++c) {
        for (int s = 0; s <= L; ++s) {
          if (!f[p][c][s]) {
            continue;
          }
          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 344 KB Output is correct
5 Correct 0 ms 860 KB Output is correct
6 Correct 0 ms 860 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 860 KB Output is correct
10 Correct 0 ms 348 KB Output is correct

Subtask #2
15.0 / 15.0

# 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 600 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 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 0 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 344 KB Output is correct
5 Correct 0 ms 860 KB Output is correct
6 Correct 0 ms 860 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 860 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 600 KB Output is correct
14 Correct 1 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 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 0 ms 348 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 600 KB Output is correct
22 Correct 21 ms 4056 KB Output is correct
23 Correct 18 ms 5820 KB Output is correct
24 Correct 16 ms 4440 KB Output is correct
25 Correct 19 ms 5884 KB Output is correct
26 Correct 19 ms 5080 KB Output is correct
27 Correct 7 ms 1884 KB Output is correct
28 Correct 9 ms 2216 KB Output is correct
29 Correct 16 ms 3676 KB Output is correct
30 Correct 20 ms 6044 KB Output is correct