LeetCode-Same Tree

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