Hi, here’s your problem today. This problem was recently asked by Twitter:

Given a tree, find if the binary tree is height balanced or not. A height balanced binary tree is a tree where every node’s 2 subtree do not differ in height by more than 1.

Here’s some starter code:

class Node:
  def __init__(self, value, left=None, right=None):
    self.value = value
    self.left = left
    self.right = right

def is_height_balanced(tree):
  # Fill this in.

#     1
#    / \
#   2   3
#  /
# 4  
n4 = Node(4)
n3 = Node(3)
n2 = Node(2, n4)
n1 = Node(1, n2, n3)

print(is_height_balanced(n1))
# True

#     1
#    / 
#   2   
#  /
# 4  
n1 = Node(1, n2)
print(is_height_balanced(n1))
# False