js实现单向链表，双向链表。

基础的数据结构可不要不会哦。

单向链表

//单向链表
function Node(val) {
    this.val = val;
    this.next = null;
}

function List(node) {
    this.node = new Node(node);
    //查找节点
    this.find = function (target) {
        let cur = this.node;
        while (cur.val !== target) {
            cur = cur.next;
            if (!cur) {
                return false
            }
        }
        return cur
    }
    //插入节点
    this.insert = function (node, target) {
        let newNode = new Node(node);
        let cur = this.find(target);
        newNode.next = cur.next;
        cur.next = newNode
    }
    //查找前一个节点
    this.findPre = function (target) {
        let cur = this.node;
        while (!cur.next && cur.next.val !== target) {
            cur = cur.next
        }
        return cur;
    }
    //删除节点
    this.delete = function (target) {
        let deleteNode = this.find(target);
        this.findPre(deleteNode).next = deleteNode.next
    }
}

//测试
let list = new List('pyx')
list.insert('wyt', 'pyx')
list.delete('pyx')
console.log(list.find('pyx'));
console.log(list.find('wyt'));

双向链表

//双向链表
function Node(val) {
    this.val = val;
    this.pre = null;
    this.next = null
}

function List(node) {
    this.node = new Node(node);
    this.find = function (target) {
        let cur = this.node;
        while (cur.val !== target) {
            cur = cur.next;
            if (cur === null) {
                return false
            }
        }
        return cur
    }
    this.insert = function (node, target) {
        let cur = this.find(target);
        let newNode = new Node(node);
        newNode.next = cur.next;
        newNode.pre = cur;
        // cur.next.pre = newNode;
        cur.next = newNode
    }
    this.delete = function (target) {
        let cur = this.find(target);
        cur.pre.next = cur.next;
        cur.next.pre = cur.pre;
    }
}

let list = new List('pyx')
list.insert('wyt', 'pyx')
list.insert('wyt1', 'wyt')
list.delete('wyt')
console.log(list);

记录记录！