Submission #1177608

#	Time	Username	Problem	Language	Result	Execution time	Memory
1177608		mychecksedad	Skyscraper (JOI16_skyscraper)	C++20	100 / 100	137 ms	242788 KiB

skyscraper

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 100+5, M = 1000+10, K = 52, MX = 30;


int n, a[N], L, d[N];
ll dp[N][N][M][3];
void solve(){
  cin >> n >> L;
  for(int i = 1; i <= n; ++i){
    cin >> a[i];
  }
  if(n == 1){
    cout << 1;
    return;
  }
  for(int i = 0; i <= n; ++i){
    for(int j = 0; j <= n; ++j) for(int x = 0; x <= L; ++x) for(int y = 0; y <= 2; ++y) dp[i][j][x][y] = 0;
  }
  sort(a+1, a+1+n);
  for(int i = 1; i <= n; ++i){
    a[i - 1] = a[i];
  }
  for(int i = 1; i <= n; ++i){
    d[i - 1] = a[i] - a[i - 1];
  }
  dp[1][1][2 * d[0]][0] = 1;
  dp[1][1][d[0]][1] = 2;

  for(int i = 1; i < n; ++i){
    for(int j = 1; j <= i + 1; ++j){
      for(int k = 0; k <= L; ++k){
        for(int l = 0; l <= 2; l++) dp[i][j][k][l] %= MOD;
        // l == 0
        if(k + (2*j+2) * d[i] <= L) dp[i + 1][j + 1][k + (2*j+2) * d[i]][0] += dp[i][j][k][0] * (j + 1);
        if(k + (2*j+1) * d[i] <= L) dp[i + 1][j + 1][k + (2*j+1) * d[i]][1] += dp[i][j][k][0] * 2;
        if(k + (2*j-1) * d[i] <= L) dp[i + 1][j][k + (2*j-1) * d[i]][1] += dp[i][j][k][0] * 2;
        // if(i + 1 == 3 && j == 1){
        //   cout << dp[i][j][k][0] << ' ' << k + (2*j-1)*d[i] << ' ' << k << ' ' << " f\n";
        // }
        if(k + (2*j) * d[i] <= L) dp[i + 1][j][k + (2*j) * d[i]][0] += dp[i][j][k][0] * 2 * j;
        if(k + (2*j-2) * d[i] <= L) dp[i + 1][j - 1][k + (2*j-2) * d[i]][0] += dp[i][j][k][0] * (j - 1);

        // l == 1
        if(k + (2*j+1) * d[i] <= L) dp[i + 1][j + 1][k + (2*j+1)*d[i]][1] += dp[i][j][k][1] * j;
        if(k + (2*j) * d[i] <= L) dp[i + 1][j + 1][k + (2*j)*d[i]][2] += dp[i][j][k][1] * 1;
        if(k + (2*j-2) * d[i] <= L && (j > 1 || i == n-1)) dp[i + 1][j][k + (2*j-2)*d[i]][2] += dp[i][j][k][1] * 1;
        if(k + (2*j-1) * d[i] <= L) dp[i + 1][j][k + (2*j - 1)*d[i]][1] += dp[i][j][k][1] * (2*j-1);
        if(k + (2*j-3) * d[i] <= L) dp[i + 1][j - 1][k + (2*j - 3)*d[i]][1] += dp[i][j][k][1] * (j - 1);

        // l == 2
        if(k + (2*j) * d[i] <= L) dp[i + 1][j + 1][k + (2*j) * d[i]][2] += dp[i][j][k][2] * (j - 1);
        if(k + (2*j-2) * d[i] <= L) dp[i + 1][j][k + (2*j-2) * d[i]][2] += dp[i][j][k][2] * (2*j - 2);
        if(k + (2*j-4) * d[i] <= L && (j >= 3 || i == n-1)) dp[i + 1][j - 1][k + (2*j-4) * d[i]][2] += dp[i][j][k][2] * (j - 1);
      }
    }
  }
  ll sum = 0;
  for(int i = 0; i <= L; ++i){
    sum += dp[n][1][i][2];
    sum %= MOD; 
  }
  cout << sum;
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

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