oj.uz

Submission #1047224

# Submission time Handle Problem Language Result Execution time Memory
1047224 2024-08-07T11:03:52 Z nima_aryan Skyscraper (JOI16_skyscraper) C++17
100 / 100
 61 ms 6108 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) {
          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 344 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 348 KB Output is correct
5 Correct 0 ms 856 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 0 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 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 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 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 344 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 348 KB Output is correct
5 Correct 0 ms 856 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 0 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 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 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 0 ms 348 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Correct 39 ms 4008 KB Output is correct
23 Correct 55 ms 6052 KB Output is correct
24 Correct 43 ms 4712 KB Output is correct
25 Correct 57 ms 6108 KB Output is correct
26 Correct 50 ms 5468 KB Output is correct
27 Correct 16 ms 1820 KB Output is correct
28 Correct 20 ms 2140 KB Output is correct
29 Correct 36 ms 3644 KB Output is correct
30 Correct 61 ms 6056 KB Output is correct