JavaScript - Queues(Priority Queue)

Data Structures and Algorithms With Javascript
(O'Reilly Media)
Michael McMillan(著)

開発環境

• OS X Yosemite - Apple (OS)
• Emacs (Text Editor)
• JavaScript (プログラミング言語)
• SpiderMonkey (JavaScript engine)

Data Structures and Algorithms With Javascript (Michael McMillan(著)、O'Reilly Media)のChapter 5(Queues)、Exercises 3.(No. 3595)を解いてみる。

Exercises 3.(No. 3595)

JavaScript(Emacs)

/*jslint         browser : true, continue : true,
  devel  : true, indent  : 4,    maxerr   : 50,
  newcap : true, nomen   : true, plusplus : false,
  regexp : true, sloppy  : true, vars     : false,
  white  : false
*/

/*global print */
var Queue = function () {
        this.data_store = [];
    },
    Patient = function (name, code) {
        this.name = name;
        this.code = code;
    },
    ed = new Queue(),
    seen;

Queue.prototype.enqueue = function (element) {
    this.data_store.push(element);
};
Queue.prototype.dequeue = function () {
    return this.data_store.shift();
};
Queue.prototype.front = function () {
    return this.data_store[0];
};
Queue.prototype.back = function () {
    return this.data_store[this.data_store.length - 1];
};
Queue.prototype.toString = function () {
    var result = '',
        i,
        max;
    for (i = 0, max = this.data_store.length; i < max - 1; i += 1) {
        result += this.data_store[i] + ',';
    }
    result += this.data_store[i];
    return result;
};
Queue.prototype.isEmpty = function () {
    return this.data_store.length === 0 ? true : false;
};
Queue.prototype.count = function () {
    return this.data_store.length;
};

ed.dequeue = function () {
    var entry = 0,
        i,
        max;

    for (i = 0, max = this.data_store.length; i < max; i += 1) {
        if (this.data_store[i].code > this.data_store[entry].code) {
            entry = i;
        }
    }
    return this.data_store.splice(entry, 1);
};

ed.toString = function () {
    var result = '',
        i,
        max;

    for (i = 0, max = this.data_store.length; i < max; i += 1) {
        result += this.data_store[i].name + ' code: '
            + this.data_store[i].code + '\n';
    }
    return result;
};

ed.enqueue(new Patient('Smith', 5));
ed.enqueue(new Patient('Jones', 4));
ed.enqueue(new Patient('Fehrenbach', 6));
ed.enqueue(new Patient('Brown', 1));
ed.enqueue(new Patient('Ingram', 1));

print(ed.toString());
seen = ed.dequeue();
print('Patient being treated: ' + seen[0].name);
print('Patients waiting to be seen: ');
print(ed.toString());

seen = ed.dequeue();
print('Patient begin treated: ' + seen[0].name);
print('Patients waiting to be seen: ');
print(ed.toString());

seen = ed.dequeue();
print('Patient begin treated: ' + seen[0].name);
print('Patients waiting to be seen: ');
print(ed.toString());

seen = ed.dequeue();
print('Patient begin treated: ' + seen[0].name);
print('Patients waiting to be seen: ');
print(ed.toString());

出力結果(Terminal, shell, SpiderMonkey)

$ jslint sample3.js

sample3.js is OK.
$ js sample3.js
Smith code: 5
Jones code: 4
Fehrenbach code: 6
Brown code: 1
Ingram code: 1

Patient being treated: Fehrenbach
Patients waiting to be seen: 
Smith code: 5
Jones code: 4
Brown code: 1
Ingram code: 1

Patient begin treated: Smith
Patients waiting to be seen: 
Jones code: 4
Brown code: 1
Ingram code: 1

Patient begin treated: Jones
Patients waiting to be seen: 
Brown code: 1
Ingram code: 1

Patient begin treated: Brown
Patients waiting to be seen: 
Ingram code: 1

$