new_contents: """Leetcode 270. Closest Binary Search Tree Value
  Easy
  
  URL: https://leetcode.com/problems/closest-binary-search-tree-value/
  
  Given a non-empty binary search tree and a target value, find the value in the
  BST that is closest to the target.
  
  Note:
  - Given target value is a floating point.
  - You are guaranteed to have only one unique value in the BST that is closest to
    the target.
  
  Example:
  Input: root = [4,2,5,1,3], target = 3.714286
      4
     / \
    2   5
   / \
  1   3
  Output: 4
  """
  
  
  # Definition for a binary tree node.
  class TreeNode(object):
      def __init__(self, val):
          self.val = val
          self.left = None
          self.right = None
  
  
  class Solution(object):
      def closestValue(self, root, target):
          """
          :type root: TreeNode
          :type target: float
          :rtype: int
          """
          pass
  
  
  if __name__ == '__main__':
      main()
  
subject: Add lc0270_closest_binary_search_tree_value.py