Description
https://leetcode.com/problems/same-tree/description/
Given two binary trees, 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: 1 1 / \ / \ 2 3 2 3 [1,2,3], [1,2,3] Output: true
Example 2:
Input: 1 1 / \ 2 2 [1,2], [1,null,2] Output: false
Example 3:
Input: 1 1 / \ / \ 2 1 1 2 [1,2,1], [1,1,2] Output: false
Explanation
Our goal is to implement isSameTree(TreeNode p, TreeNode q) function.
There are two scenarios for isSameTree(TreeNode p, TreeNode q) to return true:
- p and q are both null
- when p and q aren’t null, p and q should have same value and p’s left and right subtrees should be same as q’s left and q.right subtrees.
Video Tutorial
Java Solution
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if (p == null && q == null) { return true; } if (p != null && q != null) { if (p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right)) { return true; } } return false; } }