Detect if the max heap property is violated in a binary tree

detect_max_heap_property.rb

#!/usr/bin/ruby

# Detect if property of max heap is violated.
# Heap is a tree-based data structure.
# Here we use a binary tree.
# Must be monotonically decreasing from parent to child.

class Node
  def initialize(value, left, right)
    @value = value
    @left = left
    @right = right
  end
  
  attr_reader :value, :left, :right
end

def hasMaxHeapProperty(node)
  
  # return false if the left CHILD or left SUBTREE is messed up	
  return false if !node.left.nil? && 
    (node.left.value > node.value || 
     !hasMaxHeapProperty(node.left))
  
  # return false if the right CHILD or right SUBTREE is messed up
  return false if !node.right.nil? &&
    (node.right.value > node.value ||
     !hasMaxHeapProperty(node.right))

  # if neither child nor subtree is messed up, we're good
  return true

end


n = Node.new(5,
             Node.new(6, 
                      Node.new(9, nil, nil),
                      nil), 
             Node.new(7,
                      Node.new(35, nil, nil),
                      Node.new(42, nil, nil))
             )

n2 = Node.new(5, nil, Node.new(6, nil, nil))
n3 = Node.new(6, nil, Node.new(6, nil, nil))


if hasMaxHeapProperty(n3)
  puts "Okay"
else
  puts "Not okay"
end