oj.uz

Submission #1047227

# Submission time Handle Problem Language Result Execution time Memory
1047227 2024-08-07T11:05:31 Z nima_aryan Skyscraper (JOI16_skyscraper) C++17
100 / 100
 20 ms 6052 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(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 1 ms 600 KB Output is correct
2 Correct 0 ms 344 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 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 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 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 1 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct

Subtask #3
80.0 / 80.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB Output is correct
2 Correct 0 ms 344 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 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 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 0 ms 348 KB Output is correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 1 ms 604 KB Output is correct
22 Correct 20 ms 3928 KB Output is correct
23 Correct 18 ms 5980 KB Output is correct
24 Correct 17 ms 4680 KB Output is correct
25 Correct 19 ms 6052 KB Output is correct
26 Correct 17 ms 5208 KB Output is correct
27 Correct 7 ms 1884 KB Output is correct
28 Correct 10 ms 2148 KB Output is correct
29 Correct 16 ms 3592 KB Output is correct
30 Correct 19 ms 5944 KB Output is correct