javascript实现优先队列

/*--------------Queue类的定义和测试代码----------------*/
function Queue(){
        this.dataStore = [];
        this.enqueue = enqueue;
        this.dequeue = dequeue;
        this.front = front;
        this.back = back;
        this.toString = toString;
        this.empty = empty;
}

//入队，就是在数组的末尾添加一个元素
function enqueue(element){
    this.dataStore.push(element);
}
//出队，判断优先级删除，注意这里用的是数组的splice方法，不是slice方法
function dequeue(){
    var priority = this.dataStore[0].code;
    var fromIndex = 0;
    for (var i=1; i<this.dataStore.length; ++i) {
        if (this.dataStore[i].code < priority) {
            fromIndex = i;
        }
    }
    return this.dataStore.splice(fromIndex, 1);
}
//取出数组的第一个元素
function front(){
    return this.dataStore[0];
}
//取出数组的最后一个元素
function back(){
    return this.dataStore[this.dataStore.length-1];
}

function toString(){
    var retStr = "";
    for (var i=0; i<this.dataStore.length; ++i) {
        retStr += "病人：" + this.dataStore[i].name + " 优先级:" + this.dataStore[i].code + "<br>"
    }
    return retStr;
}
//判断数组是否为空
function empty(){
    if(this.dataStore.length == 0){
        return true;
    }else{
        return false;
    }
}
//返回数组中元素的个数
function count(){
    return this.dataStore.length;
}

/*----------------基数排序-----------------*/

function Patient(name, code){
    this.name = name;
    this.code = code;
}
var p = new Patient(‘smith‘, 5);
var ed = new Queue();
ed.enqueue(p);

p = new Patient(‘jones‘, 4);
ed.enqueue(p);

p = new Patient(‘fehrendbach‘, 6);
ed.enqueue(p);

p = new Patient(‘brown‘, 1);
ed.enqueue(p);

p = new Patient(‘ingram‘, 1);
ed.enqueue(p);

document.write(ed.toString());

var seen = ed.dequeue();
document.write(‘<br>‘);
document.write("服务病人：" + seen[0].name);

document.write(‘<br>‘);
document.write(ed.toString());

seen = ed.dequeue();
document.write(‘<br>‘);
document.write("服务病人：" + seen[0].name);

document.write(‘<br>‘);
document.write(ed.toString());

seen = ed.dequeue();
document.write(‘<br>‘);
document.write("服务病人：" + seen[0].name);

document.write(‘<br>‘);
document.write(ed.toString());

输出结果为：