/*

* @lc app=leetcode.cn id=94 lang=javascript

*

* [94] 二叉树的中序遍历

*/

// @lc code=start

/**

* 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} root

* @return {number[]}

*/

var inorderTraversal = function(root) {

if (!root) return ;

let res = [];

let traversal = (root) => {

root.left && traversal(root.left);

res.push(root.val);

root.right && traversal(root.right);

}

traversal(root);

return res;

};

// @lc code=end

// Usage

let BTree = require("./BTree");

let root = new BTree([1,2,3,4,null,null,5]);

inorderTraversal(root);