comefrom: <doocs>0111.Minimum Depth of Binary Tree_1.py
code: def dfs(root):
      if root is None:
          return 0
      if root.left is None:
          return 1 + dfs(root.right)
      if root.right is None:
          return 1 + dfs(root.left)
      return 1 + min(dfs(root.left), dfs(root.right))
masked: def sample_funcname ( var_1 ) :
      if var_1 is None :
          return 0
      if var_1.left is None :
          return 1 + var_0 ( var_1.right )
      if var_1.right is None :
          return 1 + var_0 ( var_1.left )
      return 1 + min ( var_0 ( var_1.left ) , var_0 ( var_1.right ) )
  