数据结构之列表-javascript实现

学习数据结构的记录

列表是一种数据项构成的有限序列，即按照一定的线性顺序，排列而成的数据项的集合，在这种数据结构上进行的基本操作包括对元素的的查找，插入，和删除

列表的两种主要表现是数组和链表，栈和队列是两种特殊类型的列表

迭代器（iterator）有时又称游标（cursor）是程序设计的软件设计模式，可在容器（container，例如链表或阵列）上遍访的接口，设计人员无需关心容器的内容

front,end,prev,next使用了迭代器的原理

‘use strict‘
    function List(){
        this.size = 0;
        this.pos = 0;
        this.data = [];
        this.clear = clear;
        this.find = find;
        this.toString = toString;
        this.insert = insert;
        this.append = append;
        this.remove = remove;
        this.front = front;
        this.end = end;
        this.prev = prev;
        this.next = next;
        this.length = length;
        this.currPos = currPos;
        this.moveTo = moveTo;
        this.getElement = getElement;
        this.contains = contains;
    };
    function append(element){
        this.data[this.size++] = element;
    }
    function find(element){
        for(var i = 0; i < this.data.length; i++){
            if(this.data[i] == element){
                return i;
            }
        }
        return -1;
    }
    function remove(element){
        var foundAt = this.find(element);
        if(foundAt > -1){
            this.data.splice(foundAt,1);
            --this.size;
            return true;
        }
        return false;
    }
    function length(){
        return this.size;
    }
    function toString(){
        return this.data;
    }
    function insert(element, after){
        var insertPos = this.find(after);
        if(insertPos > -1){
            this.data.splice(insertPos+1, 0, element);
            ++this.size;
            return true;
        }
        return false;
    }
    function clear(){
        delete this.data;
        this.data.length = 0;
        this.size = this.pos = 0;
    }
    /*判断查询元素是否在列表内*/
    function contains(element){
        for (var i = 0; i < this.data.length; i++) {
            if(this.data[i] == element){
                return true;
            }
        }
        return false
    }
    /*移动到第一个元素*/
    function front(){
        this.pos = 0;
    }
    /*移动到最后一个元素*/
    function end(){
        this.pos = this.size - 1;
    }
    function prev(){
        if(this.pos > 0){
            --this.pos;
        }
    }
    function next(){
        if(this.pos < this.size -1){
            ++this.pos;
        }
    }
    function currPos(){
        return this.pos;
    }
    function getElement(){
        return this.data[this.pos];
    }

    var names = new List();
    names.append(‘lily‘);
    names.append(‘tom‘);
    names.append(‘king‘);
    names.append(‘lihua‘);
    names.append(‘lisi‘);

    names.front();
    console.log(names.getElement()) //lily

    names.next();
    console.log(names.getElement()) //tom

    var asd = names.find(‘king‘)
    console.log(asd)                //2

    names.insert(‘jacks‘, ‘king‘)
    console.log(names.data)         //["lily", "tom", "king", "jacks", "lihua", "lisi"]