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 binary tree * 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){ return false; } if(p != null || q == null){ return false; } if(p.val == q.val){ return (isSameTree(p.left, q.left)) && isSameTree(p.right, q.right); } else { return false; } } }