fork download
copy 
  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define int long long
  4. #define ii pair<int, int>
  5. #define F first
  6. #define S second
  7. const int N = 20, M = 1e9+7, inf = 1e18;
  8. int n, m, dp[2005][15][2005];
  9. signed main()
  10. {
  11.     //freopen("main.inp", "r", stdin);
  12.     //freopen("main.out", "w", stdout);
  13.     ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  14.     cin >> n >> m;
  15.     dp[0][n][0] = 1;
  16.     for(int i = 1; i <= m; i++) {
  17.         for(int msk = 0; msk < (1 << n); msk++) dp[i][0][msk] = dp[i-1][n][msk];
  18.         for(int j = 1; j <= n; j++) {
  19.             for(int msk = 0; msk < (1 << n); msk++) {
  20.                 bool use = (1 << (j-1)) & msk;
  21.                 if(use) dp[i][j][msk] += dp[i][j-1][msk-(1 << (j-1))];
  22.                 else {
  23.                     dp[i][j][msk] += dp[i][j-1][msk+(1<<(j-1))];
  24.                     if(j > 1 && !((1 << (j-2)) & msk)) dp[i][j][msk] += dp[i][j-2][msk];
  25.                 }
  26.                 dp[i][j][msk] %= M;
  27.             }
  28.         }
  29.     }
  30.     cout << dp[m][n][0];
  31.     return 0;
  32. }
Success #stdin #stdout 0s 5300KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
1
https://ideone.com/znEpmz
language:
C++14 (gcc 8.3)
created:
8 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!