LeetCode 100. Same Tree

問題：判斷兩組二元樹是否相同

解法：透過遞迴方式將兩組的左右枝幹透過遞迴判斷，條件如下

1.節點與節點都等於null，回傳true

2.節點與節點不等於null，回傳false

3.節點與節點指到的下一個節點不相同，回傳false JavaScript

/**
 * 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) {
        return false;
    } else if (p.val != q.val) {
        return false;
    }

    return isSameTree(p.right, q.right) && isSameTree(p.left, q.left);
};