Algo & DS - Binary Search Tree operations challenge

challenge.rb

class Node
	attr_reader :data
	attr_accessor :left, :right
	
	def initialize data
		@data = data
	end
end
def array_to_tree(array, index = 0)
	# use your function from the previous challenge
	if index >= array.length || array[index] == 0
		return nil
	end
	node = Node.new(array[index])
	node.left = array_to_tree(array, 2*index+1)
	node.right = array_to_tree(array, 2*index+2)
	return node
end
def search_tree_helper(node, min = nil, max = nil)
	return true if node.nil?
	return false if min != nil && node.data <= min
	return false if max != nil && node.data >= max
	search_tree_helper(node.left, min, node.data) && search_tree_helper(node.right, node.data, max)
end
def search_tree?(array)
	root = array_to_tree(array)
  # write your code here
	return search_tree_helper(root)
end

puts search_tree?([10, 4, 12])
# => true
puts search_tree?([10, 5, 7])
# => false