new_contents: """Leetcode 700. Search in a Binary Search Tree
  Easy
  
  URL: https://leetcode.com/problems/search-in-a-binary-search-tree/
  
  Given the root node of a binary search tree (BST) and a value.
  You need to find the node in the BST that the node's value equals the given value.
  Return the subtree rooted with that node. 
  If such node doesn't exist, you should return NULL.
  
  For example, 
  Given the tree:
          4
         / \
        2   7
       / \
      1   3
  And the value to search: 2
  You should return this subtree:
        2     
       / \   
      1   3
  In the example above, if we want to search the value 5, since there is no node
  with value 5, we should return NULL.
  
  Note that an empty tree is represented by NULL, therefore you would see the
  expected output (serialized tree format) as [], not null.
  """
  
  # 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 searchBST(self, root, val):
          """
          :type root: TreeNode
          :type val: int
          :rtype: TreeNode
          """
          pass
  
  
  def main():
      pass
  
  
  if __name__ == '__main__':
      main()
  
subject: Add lc0700_search_in_a_binary_search_tree.py