每日算法题 - Floor and Ceiling of a Binary Search Tree

Hi, here's your problem today. This problem was recently asked by Apple:

Given an integer k and a binary search tree, find the floor (less than or equal to) of k, and the ceiling (larger than or equal to) of k. If either does not exist, then print them as None.

Here is the definition of a node for the tree.

class Node:

  def __init__(self, value):

    self.left = None

    self.right = None

    self.value = value



def findCeilingFloor(root_node, k, floor=None, ceil=None):

  # Fill this in.



root = Node(8) 

root.left = Node(4) 

root.right = Node(12) 

  

root.left.left = Node(2) 

root.left.right = Node(6) 

  

root.right.left = Node(10) 

root.right.right = Node(14) 



print findCeilingFloor(root, 5)

# (4, 6)