ES6 实现 二叉树 前序 中序 后序

Question

// 创建节点
function Node(data, left, right) {
  this.data = data
  this.left = left
  this.right = right
  this.show = function () {
    return this.data
  }
}
// 创建二叉树
function BST() {
  //根节点
  this.root = null
  //插入节点
  this.insert = insert
  this.getMin = getMin
  this.getMax = getMax
  this.find = find
}

function insert(data) {
  var n = new Node(data, null, null)
  if (this.root === null) {
    this.root = n
  } else {
    var current = this.root
    var parent
    while (true) {
      parent = current
      if (data < current.data) {
        //左节点
        current = current.left
        if (current === null) {
          parent.left = n
          break
        }
      } else {
        //右节点
        current = current.right
        if (current === null) {
          parent.right = n
          break
        }
      }
    }
  }
}
// 最小值
function getMin() {
  var current = this.root
  while (!(current.left === null)) {
    current = current.left
  }
  return current.data
}
//最大值
function getMax() {
  var current = this.root
  while (!(current.right === null)) {
    current = current.right
  }
  return current.data
}

// 查找二叉树
function find(data) {
  var current = this.root
  // 递归查找
  // 在BST上查找给定值，需要比较该值和当前节点上 的值的大小。
  // 通过比较，就能确定如果给定值不在 当前节点时，该向左遍历还是向右遍历。
  while (current != null) {
    if (current.data == data) {
      return current;
    } else if (data < current.data) {
 current.left; 
} else {
 current.right;
 } 
} 
return null 
} 
var bst = new BST()
 var datas = [23, 45, 16, 37, 3, 99, 22];
 datas.forEach(key => {
  bst.insert(key)
});
var min = bst.getMin()
console.log('最小值' + min)
var max = bst.getMax()
console.log('最大值' + max)

var found = bst.find(10);
console.log(found);

if (found != null) {
  console.log('This value is find in BST');
} else {
  console.log('This value is not in BST');
}