Recursive Binary Tree Solution - Same Tree

Recursive function to compare node, left and right at the same time (differentiate to symmetric, one.l vs two.right and one.right vs two.left).

/**
 * 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){
            return q == null;
        }
        if(q == null){
            return p == null;
        }
        if(p.val == q.val){
            return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
        }
        return false;
    }
}