100. Same Tree — LeetCode Solution

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

Here is my solution:

/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
public boolean isSameTree(TreeNode p, TreeNode q) {
if (p == null && q == null) {
return true;
}
if (p == null || q == null) {
return false;
}

return p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
}
}

You can checkout the full explanation by watching the below video: