四人过桥js简单实现

一座桥，同时只能两个人过桥，他们共用一个手电筒。现有四个人，
每个人的过桥时间都不一样，分别为：10、5、2、1。怎样让他们用最短的时间过去。
<html lang="zh-cn">
<head>
<meta charset="utf-8"/>

<script type="text/javascript">
<!--
    // 一座桥，同时只能两个人过桥，他们共用一个手电筒。现有四个人，
    //每个人的过桥时间都不一样，分别为：10、5、2、1。怎样让他们用最短的时间过去。

    var passer = function(name,time){
        this.name = name;
        this.time = time;
    }
    
    passer.prototype = {
        //重写toString方法  
        toString : function() {  
            return this.name;  
        }
    }

    var passBridge=function(tempArr){
        this.backarray = [];         //未过桥数组
        this.passarray = [];         //过桥数组
        this.backarray = tempArr;
        
        this.amounttime = 0;  //总时长
        this.passcount = 1;   //过桥次数
        document.write("共" + this.backarray.length + "人:" + this.backarray + ".<br>" + this.description() + "<br><br><br>");
    }
    
    passBridge.prototype.description = function (){
        var res="";    
        for(var o in this.backarray){    
            res+=(this.backarray[o].name+"的时间是"+ this.backarray[o].time +"<br>");//从当前this对象读取构造器中的属性对应的值    
        }    
        return res;
    }

    passBridge.prototype.pass = function(){
        var first,second;
        var lastone,lasttwo;
        this.backarray.sort(function(a,b){return a.time - b.time;});
        if(this.passcount % 2 != 0){   //单次数过桥，由未过桥数组中最小的两个人过桥
            first = this.backarray[0];
            second = this.backarray[1];
            this.amounttime += second.time;
            this.backarray.splice(0,2);
            document.write(first.name + second.name +"过桥：" + this.backarray + "  ____________"+ first.name +"웃"+ second.name +"웃⇢_________  " + this.passarray + "<br>" + "用时：" +second.time + "<br>");
            this.passarray.push(first);
            this.passarray.push(second);
        }else{                            //双次数过桥，由未过桥数组中最大的两个人过桥
            lastone = this.backarray[this.backarray.length-1];
            lasttwo = this.backarray[this.backarray.length-2];
            this.amounttime += lastone.time;
            this.backarray.splice(this.backarray.length-2,2);
            document.write(lastone.name + lasttwo.name +"过桥：" + this.backarray + "  ____________"+ lastone.name  +"웃"+ lasttwo.name +"웃⇢_________  " + this.passarray + "<br>" + "用时：" +lastone.time + "<br>");
            this.passarray.push(lastone);
            this.passarray.push(lasttwo);
        }
        this.passcount++;
        if(this.backarray.length == 0){            
            document.write("<br><br><br>成功过桥,总时长为:" + this.amounttime);
        }else{
            this.back();
        }
    }

    passBridge.prototype.back = function(){
        this.passarray.sort(function(a,b){return a.time - b.time;});
        var temp = this.passarray[0]
        this.amounttime += this.passarray[0].time;
        //document.write(this.passarray[0].name + "正在返回,<br><br><br>时间为:" + this.passarray[0].time + "。没过桥的有" + this.backarray);
        this.passarray.splice(0,1);
        document.write(temp.name +"返回：" + this.backarray + "  ___________⇠웃"+ temp.name +"__________  " + this.passarray + "<br>" + "用时：" +temp.time + "<br><br><br>");
        this.backarray.push(temp);
        this.pass();
    }
 
    var tempArr = [new passer('a',1),new passer('b',2),new passer('c',5),new passer('d',10),new passer('e',11),new passer('f',12)];
    var main = new passBridge(tempArr);
    window.onload = main.pass();
//-->
</script>
</head>
</html>
由什么需要改进的，希望看官能提出来。