/*

* 优先队列

* 出队时，先找出优先级最高的元素，再按照先进先出出队。

* */

function Queue(){

    this.dataStore = [];//存放队列的数组，初始化为空

    this.enqueue = enqueue;//向队列尾部添加一个元素

    this.dequeue = dequeue;//出队时，先找出优先级最高的元素，再按照先进先出出队。

    this.theFront = theFront;//读取队首的元素

    this.back = back;//对取队尾的元素

    this.toStrings = toStrings;//显示队列内的所有元素

    this.empty = empty;//判断队列是否为空

}

/*先定义存储队列元素的对象*/

function Patient(name,code){

    this.name = name;//code是一个整数，表示患者的优先级

    this.code = code;

}

function enqueue(element){

    this.dataStore.push(element);

}

function dequeue(){

    var minindex = 0;

    var priority = this.dataStore[0].code;

    for(var i = 1;i<this.dataStore.length;i++){

        if(this.dataStore[i].code < priority){

            priority = this.dataStore[i].code;

            minindex = i;

        }

    }

    return this.dataStore.splice(minindex,1);

}

function theFront(){

    return this.dataStore[0];

}

function back(){

    return this.dataStore[this.dataStore.length-1];

}

function toStrings(){

    return this.dataStore;

}

function empty(){

    if(this.dataStore.length == 0){

       return true;

    }else{

        return false;

    }

}

/*优先队列的实现*/

var ed = new Queue();

var p = new Patient("aa",5);

ed.enqueue(p);

var p = new Patient("bb",4);

ed.enqueue(p);

var p = new Patient("cc",3);

ed.enqueue(p);

var p = new Patient("dd",3);

ed.enqueue(p);

var p = new Patient("ee",1);

ed.enqueue(p);

console.log(ed.toStrings());

console.log(ed.dequeue());//[ Patient { name: 'ee', code: 1 } ]

console.log(ed.dequeue());//[ Patient { name: 'cc', code: 3 } ]

console.log(ed.dequeue());//[ Patient { name: 'dd', code: 3 } ]