LC100-Same-Tree.js

/*
Given the roots of two binary trees p and q, 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: p = [1,2,3], q = [1,2,3]
Output: true

Example 2:
Input: p = [1,2], q = [1,null,2]
Output: false

Example 3:
Input: p = [1,2,1], q = [1,1,2]
Output: false


Constraints:
(*) The number of nodes in both trees is in the range [0, 100].
(*) -10^4 <= Node.val <= 10^4
*/

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} p
 * @param {TreeNode} q
 * @return {boolean}
 */
var isSameTree = function(p, q) {
    if ((p===null) & (q===null)){
        return true
    } else if ((p===null) | (q==null)){
        // one of p is not null and other is null
        return false
    } else if (p.val != q.val){
        return false
    } else {
        return (isSameTree(p.left, q.left) & isSameTree(p.right, q.right))
    }
};