hello-algo/codes/javascript/modules/TreeNode.js

/**
 * File: TreeNode.js
 * Created Time: 2022-12-04
 * Author: IsChristina (christinaxia77@foxmail.com)
 */

/**
 * Definition for a binary tree node.
 */
class TreeNode {
    val; // 节点值
    left; // 左子节点指针
    right; // 右子节点指针
    height; //节点高度
    constructor(val, left, right, height) {
        this.val = val === undefined ? 0 : val;
        this.left = left === undefined ? null : left;
        this.right = right === undefined ? null : right;
        this.height = height === undefined ? 0 : height;
    }
}

/**
 * Generate a binary tree given an array
 * @param arr
 * @return
 */
function arrToTree(arr) {
    if (arr.length === 0) return null;

    let root = new TreeNode(arr[0]);
    let queue = [root];
    let i = 0;
    while (queue.length) {
        let node = queue.shift();
        if (++i >= arr.length) break;
        if (arr[i] !== null) {
            node.left = new TreeNode(arr[i]);
            queue.push(node.left);
        }
        if (++i >= arr.length) break;
        if (arr[i] !== null) {
            node.right = new TreeNode(arr[i]);
            queue.push(node.right);
        }
    }

    return root;
}

module.exports = {
    TreeNode,
    arrToTree
};