comefrom: <doocs>0552.Student Attendance Record II_1.py
code: def checkRecord( n: int) -> int:
      mod = int(1e9 + 7)
      dp = [[[0, 0, 0], [0, 0, 0]] for _ in range(n)]
      
      dp[0][0][0] = dp[0][0][1] = dp[0][1][0] = 1
      
      for i in range(1, n):
          dp[i][1][0] = (dp[i - 1][0][0] + dp[i - 1][0][1] + dp[i - 1][0][2]) % mod
          dp[i][0][1] = dp[i - 1][0][0]
          dp[i][0][2] = dp[i - 1][0][1]
          dp[i][1][1] = dp[i - 1][1][0]
          dp[i][1][2] = dp[i - 1][1][1]
          dp[i][0][0] = (dp[i - 1][0][0] + dp[i - 1][0][1] + dp[i - 1][0][2]) % mod
          dp[i][1][0] = (
              dp[i][1][0] + dp[i - 1][1][0] + dp[i - 1][1][1] + dp[i - 1][1][2]
          ) % mod
      
      ans = 0
      for j in range(2):
          for k in range(3):
              ans = (ans + dp[n - 1][j][k]) % mod
      return ans
masked: def sample_funcname ( var_0 : int ) -> int :
      var_4 = int ( 1e9 + 7 )
      var_8 = [ [ [ 0 , 0 , 0 ] , [ 0 , 0 , 0 ] ] for var_6 in range ( var_0 ) ]
      var_8 [ 0 ] [ 0 ] [ 0 ] = var_8 [ 0 ] [ 0 ] [ 1 ] = var_8 [ 0 ] [ 1 ] [ 0 ] = 1
      for var_10 in range ( 1 , var_0 ) :
          var_8 [ var_10 ] [ 1 ] [ 0 ] = ( var_8 [ var_10 - 1 ] [ 0 ] [ 0 ] + var_8 [ var_10 - 1 ] [ 0 ] [ 1 ] + var_8 [ var_10 - 1 ] [ 0 ] [ 2 ] ) % var_4
          var_8 [ var_10 ] [ 0 ] [ 1 ] = var_8 [ var_10 - 1 ] [ 0 ] [ 0 ]
          var_8 [ var_10 ] [ 0 ] [ 2 ] = var_8 [ var_10 - 1 ] [ 0 ] [ 1 ]
          var_8 [ var_10 ] [ 1 ] [ 1 ] = var_8 [ var_10 - 1 ] [ 1 ] [ 0 ]
          var_8 [ var_10 ] [ 1 ] [ 2 ] = var_8 [ var_10 - 1 ] [ 1 ] [ 1 ]
          var_8 [ var_10 ] [ 0 ] [ 0 ] = ( var_8 [ var_10 - 1 ] [ 0 ] [ 0 ] + var_8 [ var_10 - 1 ] [ 0 ] [ 1 ] + var_8 [ var_10 - 1 ] [ 0 ] [ 2 ] ) % var_4
          var_8 [ var_10 ] [ 1 ] [ 0 ] = ( var_8 [ var_10 ] [ 1 ] [ 0 ] + var_8 [ var_10 - 1 ] [ 1 ] [ 0 ] + var_8 [ var_10 - 1 ] [ 1 ] [ 1 ] + var_8 [ var_10 - 1 ] [ 1 ] [ 2 ] ) % var_4
      var_12 = 0
      for var_13 in range ( 2 ) :
          for var_15 in range ( 3 ) :
              var_12 = ( var_12 + var_8 [ var_0 - 1 ] [ var_13 ] [ var_15 ] ) % var_4
      return var_12
  