IS103 CT AY1213 Q3 Binary Tree Checker

q3_checker.rb

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# AY1213 Term 2 Finals                                     #
# Q3 Binary Tree solution checker                          #
# NOTE: This is a best-effort simple solution checker      #
#       and put together in probably the most inefficient  #
#       way. Sorry Prof Hady & Mok!                        #
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# Updated 6 Dec 17, 1115                                   #
# Feel free to comment/fork                                #
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# Write your 2 methods here, then run `ruby q3_checker.rb`
def CountTwoChildren(t)
  
end

def CountDescendents(t)
  
end

## DO NOT TOUCH ANYTHING BELOW THIS LINE UNLESS YOU KNOW WHAT YOU ARE DOING ##

COUNT_TWO_CHILDREN_EXPECTED = 4.freeze
COUNT_DESCENDENTS_EXPECTED = [9,3,1,0,0,4,0,2,0,0].freeze

class Node
  attr_accessor :leftChild, :rightChild, :descendents, :key

  def initialize(key)
    @leftChild = nil
    @rightChild = nil
    # Assume t.descendents is always initialised with 0
    @descendents = 0
    @key = key
  end
end

@descendents = []
# preorder grants us a sequential (1..10) traversal of the example tree
def traverseTreeDescendents(t)
  return if t.nil?
  @descendents << t.descendents
  traverseTreeDescendents(t.leftChild) unless t.leftChild.nil?
  traverseTreeDescendents(t.rightChild) unless t.rightChild.nil?
end

# Create Binary Tree based on Q3 Figure 2
puts 'Creating example Binary Tree...'
root_node = Node.new(1)
root_node.leftChild = Node.new(2)
root_node.leftChild.leftChild = Node.new(3) 
root_node.leftChild.leftChild.leftChild = Node.new(4)
root_node.leftChild.rightChild = Node.new(5)

root_node.rightChild = Node.new(6)
root_node.rightChild.leftChild = Node.new(7)
root_node.rightChild.rightChild = Node.new(8)
root_node.rightChild.rightChild.leftChild = Node.new(9)
root_node.rightChild.rightChild.rightChild = Node.new(10)
puts 'Tree Created'
puts ''

puts 'Calling CountTwoChildren...'
puts "Expected Answer: #{COUNT_TWO_CHILDREN_EXPECTED}"
count = CountTwoChildren(root_node)
puts "Your answer: #{count}"
puts count == COUNT_TWO_CHILDREN_EXPECTED ? '=> Correct!' : '=> WRONG ANSWER!'
puts ''

puts 'Calling CountDescendents...'
puts "Expected Answer: #{COUNT_DESCENDENTS_EXPECTED}"
CountDescendents(root_node)
traverseTreeDescendents(root_node)
puts "Your answer: #{@descendents}"
puts @descendents == COUNT_DESCENDENTS_EXPECTED ? '=> Correct!' : '=> WRONG ANSWER!'