// 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. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if(p == null && q == null) return true; if(p == null && q != null || q == null && p != null) return false; if(p.val != q.val) return false; return isSameTree(p.left, q.left) && isSameTree(p.right, q.right); } }