SOURCE

// 函数版
let strArr = 'ABEF##G##D##C##'.split('')

function Node(data = '#') {
    this.data = data
    this.lChild = null
    this.rChild = null
}

function createTreeNode(node) {
    if (strArr.length) return
    let str = strArr.shift()
    if (str === '#') return
    console.log(strArr)
    node.data = str
    if (strArr[0] !== '#') {
        node.lChild = new Node()
    }
    createTreeNode(node.lChild)

    if (strArr[0] !== '#') {
        node.rChild = new Node()
    }
    createTreeNode(node.rChild)
}

let fnTree = new Node()
createTreeNode(fnTree)
console.log(fnTree)

// 先序遍历结果
function ProOrderTraverse (node) {
    if (node === null) return
    ProOrderTraverse(node.lChild)
    ProOrderTraverse(node.rChild)
}

/*
空数组：空结点
数组：在根结点上构造左子树、右子树
*/

class BiTree {
    root = null
    arr = []
    constructor (arr) {
        this.arr = arr
        // 初始化一个结点
        this.root = new Node()
    }
    // 构建左子树、右子树、空结点
    createNode (node) {
        if (!this.arr.length) return
        const str = this.arr.shift()
        // 空结点不需要在构建左子树、右子树了
        if (str === '#') return
        node.data = str
        // 开始建立左子树
        if (this.arr[0] !== '#') {
            node.lChild = new Node(str)
        }
        this.createNode(node.lChild)

        // 构造右子树
        if (this.arr[0] !== '#') {
            node.rChild = new Node(str)
        }
        this.createNode(node.rChild)
    }
}

// 树的字符串
let strArrObj = 'ABEF##G##D##C##'.split('')

let biTreeObj = new BiTree(strArrObj)
biTreeObj.createNode(biTreeObj.root)
console.log(biTreeObj.root)