제출 #1192537

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1192537		aykhn	Skyscraper (JOI16_skyscraper)	C++20	100 / 100	145 ms	14800 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define inf 0x3F3F3F3F3F3F3F3F

const int MXN = 1e3 + 5;
const int mod = 1e9 + 7;

int dp[MXN][MXN][2][2], ndp[MXN][MXN][2][2];

void _()
{
  int n, L;
  cin >> n >> L;
  int arr[n];
  for (int &i : arr) cin >> i;
  sort(arr, arr + n);
  dp[0][1][0][0] = dp[0][1][1][0] = dp[0][1][0][1] = dp[0][1][1][1] = 1;
  int prv = 0;
  for (int &i : arr)
  {
    int val = i - prv;
    if (!prv) 
    {
      prv = i;
      continue;
    }
    prv = i;
    for (int sum = 0; sum <= L; sum++)
    {
      for (int c = 0; c <= n; c++)
      {
        for (int f = 0; f < 2; f++)
        {
          for (int b = 0; b < 2; b++)
          {
            if (!dp[sum][c][f][b]) continue;
            if (c < f + b) continue;
            int all = 2 * c - f - b;
            int nw = sum + val * all;
            if (nw > L) continue;
            int X = dp[sum][c][f][b];
            if (!f)
            {
              ndp[nw][c][1][b] += X, ndp[nw][c][1][b] %= mod;
              if (c + 1 <= n) ndp[nw][c + 1][1][b] += X, ndp[nw][c + 1][1][b] %= mod;
            }
            if (!b)
            {
              ndp[nw][c][f][1] += X, ndp[nw][c][f][1] %= mod;
              if (c + 1 <= n) ndp[nw][c + 1][f][1] += X, ndp[nw][c + 1][f][1] %= mod;
            }
            ndp[nw][c][f][b] += X * (2 * c - f - b) % mod, ndp[nw][c][f][b] %= mod;
            if (c + 1 <= n) ndp[nw][c + 1][f][b] += X * (c + 1 - f - b) % mod, ndp[nw][c + 1][f][b] %= mod;
            if (c >= 2) ndp[nw][c - 1][f][b] += X * (c - 1) % mod, ndp[nw][c - 1][f][b] %= mod;
          }
        }
      }
    }
    for (int sum = 0; sum <= L; sum++) for (int c = 0; c <= n; c++) for (int f = 0; f < 2; f++) for (int b = 0; b < 2; b++) dp[sum][c][f][b] = ndp[sum][c][f][b], ndp[sum][c][f][b] = 0;
  }
  int res = 0;
  for (int i = 0; i <= L; i++)
  {
    res += dp[i][1][1][1];
    res %= mod;
  }
  cout << res << '\n';
}
signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t = 1;
  // cin >> t;
  while (t--) _();
}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80