parameters: (self, root, k)
return_statement: return False
docstring: :type root: TreeNode
          :type k: int
          :rtype: bool
docstring_summary: :type root: TreeNode
          :type k: int
          :rtype: bool
docstring_tokens: : type root : TreeNode : type k : int : rtype : bool
function: def findTarget(self, root, k):
          """
          :type root: TreeNode
          :type k: int
          :rtype: bool
          """
          class BSTIterator(object):
              def __init__(self, root, forward):
                  self.__node = root
                  self.__forward = forward
                  self.__s = []
                  self.__cur = None
                  self.next()
  
              def val(self):
                  return self.__cur
  
              def next(self):
                  while self.__node or self.__s:
                      if self.__node:
                          self.__s.append(self.__node)
                          self.__node = self.__node.left if self.__forward else self.__node.right
                      else:
                          self.__node = self.__s.pop()
                          self.__cur = self.__node.val
                          self.__node = self.__node.right if self.__forward else self.__node.left
                          break
  
  
          if not root:
              return False
          left, right = BSTIterator(root, True), BSTIterator(root, False)
          while left.val() < right.val():
              if left.val() + right.val() == k:
                  return True
              elif left.val() + right.val() < k:
                  left.next()
              else:
                  right.next()
          return False
function_tokens: def findTarget ( self , root , k ) : class BSTIterator ( object ) : def __init__ ( self , root , forward ) : self . __node = root self . __forward = forward self . __s = [ ] self . __cur = None self . next ( ) def val ( self ) : return self . __cur def next ( self ) : while self . __node or self . __s : if self . __node : self . __s . append ( self . __node ) self . __node = self . __node . left if self . __forward else self . __node . right else : self . __node = self . __s . pop ( ) self . __cur = self . __node . val self . __node = self . __node . right if self . __forward else self . __node . left break if not root : return False left , right = BSTIterator ( root , True ) , BSTIterator ( root , False ) while left . val ( ) < right . val ( ) : if left . val ( ) + right . val ( ) == k : return True elif left . val ( ) + right . val ( ) < k : left . next ( ) else : right . next ( ) return False