JavaScript 种一颗二叉树

/*
实现一颗树
  结点类:Tree
     包含左子树left,右子树right,根节点root,缺省为null
     构造设置value
  树类:Trees
    构造:默认根节点为null
    insert:
        如果当前根节点不存在,则将传进来的节点存为根节点
        如果当前根节点存在,执行InsertTree
    insertTree(rootNode,newTree):
        1 如果新树value小于根节点value,放到根节点的左边,如果根节点左子树已经存在,以根节点左子树为根节点继续递归
        2 如果新树value大于等于根节点value,放到根节点右边,如果根节点右子树已经存在,以根节点右子树为根节点继续递归
*/
class Tree {
    left = null;
    right = null;
    root = null;
    constructor(_value) { this.value = _value;}
}
class Trees {
    constructor() { this.root = null; }
    insert(value) {this.root ? this.insertTree(this.root, new Tree(value)) : this.root = new Tree(value);}
    insertTree(rootNode, newTree) {
        newTree.value < rootNode.value ?
        (rootNode.left ? this.insertTree(rootNode.left, newTree) : rootNode.left = newTree)
        :
        (rootNode.right ? this.insertTree(rootNode.right, newTree) : rootNode.right = newTree);
    }
}
let tree = new Trees();
for (let i = 20; i > 0; i -= 2) {
    tree.insert(i - 1);
    tree.insert(i);
}
console.log(tree);