尝试为 BST 制作 'balanceFactor' 方法。无法弄清楚如何计算平衡因子...传入错误的参数？

Question

我认为我使用 'this' 不正确？我不确定如何进行。这是我正在使用的方法。

function BinarySearchTree(value) {
    this.value = value;
    this.right = null;
    this.left = null;
  }
  
  BinarySearchTree.prototype.add = function(value) {
    node = this;
  
    if (value < this.value) {
      if (this.left) this.left.add(value);
      else this.left = new BinarySearchTree(value);
    }
  
    if (value > this.value) {
      if (this.right) this.right.add(value);
      else this.right = new BinarySearchTree(value);
    }
  }

    BinarySearchTree.prototype.leftHeight = function(root = this.value) {
    if (this.value == null) {
      return 0;
    }
    let queue = [];
    queue.push(this);
    let leftHeight = 0;
  
    while (1 == 1) {
      let nodeCount = queue.length;
      if (nodeCount == 0) {
        return leftHeight - 1;
      }
      leftHeight++;
  
      while (nodeCount > 0) {
        let newNode = queue.shift();
        if (newNode.left != null) {
          queue.push(newNode.left);
        }
        nodeCount--;
      }
    }
  }

  BinarySearchTree.prototype.rightHeight = function(root = this.value) {
    if (this.value == null) {
      return 0;
    }
    let queue = [];
    queue.push(this);
    let rightHeight = 0;
  
    while (1 == 1) {
      let nodeCount = queue.length;
      if (nodeCount == 0) {
        return rightHeight - 1;
      }
      rightHeight++;
  
      while (nodeCount > 0) {
        let newNode = queue.shift();
        if (newNode.right != null) {
          queue.push(newNode.right);
        }
        nodeCount--;
      }
    }
  }

  BinarySearchTree.prototype.balanceFactor = function(this) {
      console.log(this.leftHeight)
      return this.leftHeight - this.rightHeight;
  }

这是我的输入和测试运行...

  let binarySearchTree = new BinarySearchTree;
  binarySearchTree = new BinarySearchTree(5);
  binarySearchTree.left = new BinarySearchTree(2)
  binarySearchTree.right = new BinarySearchTree(3);
  binarySearchTree.right.right = new BinarySearchTree(1);
  console.log(binarySearchTree.rightHeight());
  console.log(binarySearchTree.leftHeight());
  console.log(binarySearchTree.balanceFactor())

最后 3 个控制台记录输出 2、1 和 NaN。所以我的左右高度方法工作正常！谁能告诉我为什么我的 'balanceFactor' 方法不起作用？

谢谢，节日快乐！

Answer 1

leftHeight 和 rightHeight 是函数所以你需要这样调用它们

  BinarySearchTree.prototype.balanceFactor = function () {
    console.log(this.leftHeight())
    return this.leftHeight() - this.rightHeight();
  }

尝试为 BST 制作 'balanceFactor' 方法。无法弄清楚如何计算平衡因子...传入错误的参数？

Trying to work and make a 'balanceFactor' method for a BST. Can't figure out how to calculate the balance factor... passing in the wrong argument?

javascript

binary-search-tree