0100-same-tree.rb

# frozen_string_literal: true

# 100. Same Tree
# https://leetcode.com/problems/same-tree/
# Easy

=begin
Given the roots of two binary trees p and q, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.

Example 1:
Input: p = [1,2,3], q = [1,2,3]
Output: true

Example 2:
Input: p = [1,2], q = [1,null,2]
Output: false

Example 3:
Input: p = [1,2,1], q = [1,1,2]
Output: false
=end

# Definition for a binary tree node.
# class TreeNode
#     attr_accessor :val, :left, :right
#     def initialize(val = 0, left = nil, right = nil)
#         @val = val
#         @left = left
#         @right = right
#     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

  p.val == q.val && is_same_tree(p.left, q.left) && is_same_tree(p.right, q.right)
end