数据结构与算法--二叉树练习笔记

原文链接：https://www.cnblogs.com/SofiaTJU/p/9297164.html

---

//定义节点
class Node{
    constructor(data){
        this.root = this;
        this.data = data;
        this.left = null;
        this.right = null;
    }
}

class BinarySearchTree{
    constructor(){
        this.root = null;
    }
    //插入节点
    insert(data){
        const newNode = new Node(data);
        const insertNode = (node,newNode) => {
            if(newNode.data < node.data){
                if(node.left === null){
                    node.left = newNode
                }else{
                    insertNode(node.left,newNode)
                }
            }else{
                if(node.right === null){
                    node.right = newNode
                }else{
                    insertNode(node.right,newNode)
                }
            }
        };
        if(!this.root){
            this.root = newNode
        }else{
            insertNode(this.root,newNode)
        }
    }
    //中序排序
    inOrder(){
        let backs = [];
        const inOrderNode = (node,callback)=>{
            if(node !== null){
                inOrderNode(node.left,callback);
                backs.push(callback(node.data));
                inOrderNode(node.right,callback);
            }
        }
        inOrderNode(this.root,callback);
        function callback(v){
            return v;
        }
        return backs;
    }
    //前序遍历
    preOrder(){
        let backs = [];
        const prePostOrderNode = (node,callback)=>{
            if(node != null){
                backs.push(callback(node.data));
                prePostOrderNode(node.left,callback);
                prePostOrderNode(node.rigth,callback);
            }
        }
        prePostOrderNode(this.root,callback);
        function callback(v){
            return v;
        }
        return backs;
    }
    //后序遍历
    postOrder(){
        let backs = [];
        const postOrderNode = (node,callback)=>{
            if(node != null){
                postOrderNode(node.left,callback);
                postOrderNode(node.right,callback);
                backs.push(callback(node,data));
            }
        }
        postOrderNode(node.root,callback);
        function callback(v){
            return v;
        }
        return backs;
    }
    //查找最小值
    getMin(node){
        const minNode = node => {
            return node?(node.left?minNode(node.left):node):null
        };
        return minNode(node || this.root);
    }
    //查找最大值
    getMax(node){
        const MaxNode = node => {
            return node?(node.right?MaxNode(node.rigt):node):null
        };
        return MaxNode(node || this.root);
    }
    //查找特定值
    find(data){
        const findNode = (node,data) => {
            if(node===null) return false;
            if(node.data ==data) return node;
            return findNode((data < node.data)?node.left:node.right,data);
        }
        return findNode(this.root,data);
    }
    //删除节点
    remove(data){
        const remveNode = (node,data) => {
            if(node === null ) return null;
            if(node.data === data){
                if(node.left === null && node.right === null)return null;
                if(node.left === null) return node.right;
                if(node.right === null ) return node.right;
                if(node.left !== null && node.right !== null){
                    let _node = this.getMin(node.right);
                    node.data = _node.data;
                    node.right = removeNode(node.right,data);
                    return node;
                }
            }else if(data < node.data){
                node.left = removeNode(node.left,data);
                return node;
            }else {
                node.right = removeNode(node.right.data);
                return node;
            }
        }
        return removeNode(this.root,data);
    }
}