牛客-Corn Fields

题目传送门

sol：状压和动规，把每一行的m个01压缩成一个int

• 状压dp

  #include "bits/stdc++.h"
  using namespace std;
  const int MAXN = ;
  const int MOD = 1e8;
  int n, m;
  bool mp[MAXN][MAXN];
  vector<int> num[MAXN], dp[MAXN];
  void dfs(int i, int j, int k) {
      if (j > m) {
          num[i].push_back(k);
          dp[i].push_back();
          return;
      }
      dfs(i, j + , k  << );
      if ((k & ) ==  && mp[i][j + ] == ) dfs(i, j + , k <<  | );
  }
  int main() {
      scanf("%d%d", &n, &m);
      for (int i = ; i <= n; i++) {
          for (int j = ; j <= m; j++) scanf("%d", &mp[i][j]);
          dfs(i, , );
      }
      for (int j = ; j < dp[].size(); j++) dp[][j] = ;
      for (int i = ; i <= n; i++) {
          for (int j = ; j < dp[i].size(); j++) {
              for (int k = ; k < dp[i - ].size(); k++) {
                  if ((num[i][j] & num[i - ][k]) == )
                  {
                      dp[i][j] = (dp[i][j] + dp[i - ][k]) % MOD;
                  }
              }
          }
      }
      int ans = ;
      for (int j = ; j < dp[n].size(); j++) ans = (ans + dp[n][j]) % MOD;
      printf("%d\n", ans);
      return ;
  }