same_tree.rb

# https://leetcode.com/problems/same-tree/
#
# Given two binary trees, write a function to check if they are equal or not.
# Two binary trees are considered equal if they are structurally identical and
# the nodes have the same value.


# Definition for a binary tree node.
# class TreeNode
#   attr_accessor :val, :left, :right
#   def initialize(val)
#     @val = val
#     @left, @right = nil, nil
#   end
# end


# @param {TreeNode} p
# @param {TreeNode} q
# @return {Boolean}
def is_same_tree(p, q)
  return true if p.nil? && q.nil?
  return false if p.nil? || q.nil? || p.val != q.val
  return is_same_tree(p.left, q.left) && is_same_tree(p.right, q.right)
end