fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. #define ll long long
  5.  
  6. ll dp[100005][5][2];
  7.  
  8. int main() {
  9.     ll n;
  10.     cin >> n;
  11.  
  12.     dp[1][1][1] = 1;
  13.     dp[1][2][0] = 1;
  14.     dp[1][3][0] = 1;
  15.     dp[1][4][0] = 1;
  16.  
  17.     for (ll i = 2; i <= n; i++) {
  18.  
  19.         dp[i][1][1] = dp[i-1][1][0] + 0 + dp[i-1][3][0] + dp[i-1][4][0];
  20.         dp[i][1][0] = dp[i-1][1][1] + 0 + dp[i-1][3][1] + dp[i-1][4][1];
  21.  
  22.         dp[i][2][1] = 0 + dp[i-1][2][1] + 0 + dp[i-1][4][1];
  23.         dp[i][2][0] = 0 + dp[i-1][2][0] + 0 + dp[i-1][4][0];
  24.  
  25.         dp[i][3][1] = dp[i-1][1][1] + 0 + dp[i-1][3][1] + 0;
  26.         dp[i][3][0] = dp[i-1][1][0] + 0 + dp[i-1][3][0] + 0;
  27.  
  28.         dp[i][4][1] = dp[i-1][1][1] + dp[i-1][2][1] + 0 + dp[i-1][4][1];
  29.         dp[i][4][0] = dp[i-1][1][0] + dp[i-1][2][0] + 0 + dp[i-1][4][0];
  30.     }
  31.  
  32.     cout<<dp[n][1][1]+dp[n][2][1]+dp[n][3][1]+dp[n][4][1]<<"\n";
  33. }
Success #stdin #stdout 0s 5320KB
comments (?)
stdin
copy 
4
stdout
copy 
30
https://ideone.com/AG6PjD
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!