8/8/2019 M6-Queue

1/53

Linear Data Structures(Queue)

Teknik Informatika - Universitas Muhammadiyah Malang (UMM)

Tahun Akademik 2010-2011

Oleh : Nur Hayatin, S.ST

8/8/2019 M6-Queue

2/53

Sub Topik

Queue

Operasi Queue

Implementasi Queue Latihan

8/8/2019 M6-Queue

3/53

QUEUE

(Antrian)

8/8/2019 M6-Queue

4/53

Definisi

Urutan elemen yang mengikuti konsep FIFO.

FIFO(First In First Out)

Front menunjuk pada elemen yang palingatas.

Rear menunjuk pada elemen yang paling

belakang.

8/8/2019 M6-Queue

5/53

Gambaran Proses

Front : Depan

Rear : Belakang

8/8/2019 M6-Queue

6/53

Queue (Antrian)

Front Rear

8/8/2019 M6-Queue

7/53

Queue (Antrian)

Front Rear

8/8/2019 M6-Queue

8/53

Queue (Antrian)

Front Rear

8/8/2019 M6-Queue

9/53

Queue (Antrian)

Front Rear

8/8/2019 M6-Queue

10/53

Queue (Antrian)

FrontRear

8/8/2019 M6-Queue

11/53

Queue (Antrian)

FrontRear

8/8/2019 M6-Queue

12/53

Operasi Queue

8/8/2019 M6-Queue

13/53

Operasi

Enqueue/put

(operasi penambahan elemen)

Dequeue/remove(operasi penghapusan elemen)

Get front

(operasi pengaksesan elemen terdepan) Get rear

(operasi pengaksesan elemen paling belakang)

8/8/2019 M6-Queue

14/53

Operasi Enqueue (add)

Operasi penambahan elemen pada antrian.

Dilakukan pada rear.

Increment rear.

8/8/2019 M6-Queue

15/53

Operasi Dequeue (remove)

Operasi penghapusan elemen pada antrian.

Untuk Queue array terjadi pergeseran elemen

dari belakang ke depan. Dilakukan pada Front.

Decrement rear.

8/8/2019 M6-Queue

16/53

Operasi Get Front

Pengambilan/pengaksesan elemen yang

paling depan.

Elemen yang ditunjuk oleh front.

8/8/2019 M6-Queue

17/53

Operasi Get Rear

Pengambilan/pengaksesan elemen yang

paling belakang.

Elemen yang ditunjuk oleh rear.

8/8/2019 M6-Queue

18/53

Contoh Penerapan Queue

mailboxdalam komunikasi antar proses

simulasi dan modeling (misalnya simulasi

sistem pengendali lalu lintas udara) dalammemprediksi performansi

Waiting Line pada Sistem Operasi

8/8/2019 M6-Queue

19/53

QUEUE DENGAN CIRCULAR

ARRAY

8/8/2019 M6-Queue

20/53

Circular Array

Mampu melakukan proses penghapusan

elemen tanda melakukan pergeseran.

8/8/2019 M6-Queue

21/53

Aturan Circular Array

1. Proses penghapusan dilakukan dengan cara nilai depan

(front) ditambah 1 : depan=depan + 1.

2. Proses penambahan elemen sama dengan queue linear

array yaitu nilai belakang ditambah 1 : belakang=belakang +1.

3. Jika depan = maks dan ada elemen yang akan dihapus, maka

nilai depan = 1.

4. Jika belakang = maks dan depan tidak 1 maka jika ada

elemen yang akan ditambahkan, nilai belakang=1.

5. Jika hanya tinggal 1 elemen di queue (depan = belakang),

dan akan dihapus maka depan diisi 0 dan belakang diisi

dengan 0 (queue kosong).

8/8/2019 M6-Queue

22/53

Circular Array

8/8/2019 M6-Queue

23/53

Proses Circular Array

8/8/2019 M6-Queue

24/53

Proses Circular Array

8/8/2019 M6-Queue

25/53

Queue dalam Program

8/8/2019 M6-Queue

26/53

The Interface Queue

public interface Queue

{

public boolean isEmpty();public Object getFrontEelement();

public Object getRearEelement();

public void put(Object theObject);public Object remove();

}

8/8/2019 M6-Queue

27/53

C

lass ArrayQueue

8/8/2019 M6-Queue

28/53

Inisialisasi Awal

public class ArrayQueue implements Queue

{int front=0;

int rear=-1;

Object [] queue;

8/8/2019 M6-Queue

29/53

Constructor

public ArrayQueue(int initialCapacity)

{

if (initialCapacity < 1)

throw new IllegalArgumentException

("initialCapacity must be >= 1");

queue = new Object [initialCapacity + 1];

}

public ArrayQueue()

{

this(10);

}

8/8/2019 M6-Queue

30/53

Method empty()

public boolean isEmpty()

{

return rear == -1;

}

8/8/2019 M6-Queue

31/53

Method getFront()

public Object getFrontElement()

{if (isEmpty())

return null;

else

return queue[front];}

8/8/2019 M6-Queue

32/53

Method getRear()

public Object getRearElement()

{if (isEmpty())

return null;

else

return queue[rear];

}

8/8/2019 M6-Queue

33/53

Method put()

public void put(Object theElement)

{

if (rear == queue.length - 1){

Object [] newArray = new Object [2*queue.length];

System.arraycopy(queue, 0, newArray, 0, queue.length);

queue = newArray;

}

queue[++rear] = theElement;

}

8/8/2019 M6-Queue

34/53

Method remove()

public Object remove()

{

if (isEmpty())

return null;Object frontElement = queue[front];

for(int i = 1;i

8/8/2019 M6-Queue

35/53

Method main()public static void main(String [] args)

{

int x;

ArrayQueue q = new ArrayQueue(3);

q.put(new Integer(1)); q.put(new Integer(2));

q.put(new Integer(3)); q.put(new Integer(4));

q.remove(); q.remove();q.put(new Integer(5)); q.put(new Integer(6));

q.put(new Integer(7)); q.put(new Integer(8));

q.put(new Integer(9)); q.put(new Integer(10));

q.put(new Integer(11)); q.put(new Integer(12));

while (!q.isEmpty())

{System.out.println("Rear element is " + q.getRearElement());

System.out.println("Front element is " + q.getFrontElement());

System.out.println("Removed the element " + q.remove());

}

}

}

8/8/2019 M6-Queue

36/53

Class LinkedQueue

8/8/2019 M6-Queue

37/53

Class ChainNode

class ChainNode

{

// package visible data members

Object element;

ChainNode next;

// package visible constructors

ChainNode() {}

ChainNode(Object element)

{this.element = element;}

ChainNode(Object element, ChainNode next)

{this.element = element;

this.next = next;}

}

8/8/2019 M6-Queue

38/53

Inisialisasi Awal

public class LinkedQueue implements Queue

{

protected ChainNode front;

protected ChainNode rear;

8/8/2019 M6-Queue

39/53

Method isEmpty()

public boolean isEmpty()

{

return front == null;

}

8/8/2019 M6-Queue

40/53

Method getFront()

public Object getFrontElement()

{ if (isEmpty())

return null;

else

return front.element;}

8/8/2019 M6-Queue

41/53

Method getRear()

public Object getRearElement()

{if (isEmpty())

return null;

else

return rear.element;}

8/8/2019 M6-Queue

42/53

Method put()

public void put(Object theElement)

{

ChainNode p = new ChainNode(theElement, null);

if (front == null)

front = p; // empty queue

else

rear.next = p; // nonempty queuerear = p;

}

8/8/2019 M6-Queue

43/53

Method remove()

public Object remove()

{

if (isEmpty())

return null;

Object frontElement = front.element;

front = front.next;

if (isEmpty())

rear = null; // enable garbage collectionreturn frontElement;

}

8/8/2019 M6-Queue

44/53

Method main()

public static void main(String [] args)

{

int x;

LinkedQueue q = new LinkedQueue(3);

q.put(new Integer(1));

q.put(new Integer(2));q.put(new Integer(3));

q.put(new Integer(4));

while (!q.isEmpty())

{

System.out.println("Rear element is " + q.getRearElement());

System.out.println("Front element is " + q.getFrontElement());

System.out.println("Removed the element " + q.remove());

}

}

}

8/8/2019 M6-Queue

45/53

Class CircularQueue

8/8/2019 M6-Queue

46/53

Inisialisasi Awal

class CircularQueue

{private int maxSize;

private int[] queArray;

private int front;

private int rear;private int nItems;

8/8/2019 M6-Queue

47/53

Constructor

public CircularQueue(int s)

{

maxSize = s;queArray = new int[maxSize];

front = 0;

rear = -1;

nItems = 0;

}

8/8/2019 M6-Queue

48/53

Method isEmpty()

public boolean isEmpty(){

return (nItems==0);

}

8/8/2019 M6-Queue

49/53

Method peekFront()

public int peekFront()

{

return queArray[front];

}

8/8/2019 M6-Queue

50/53

Method insert()

public void insert(int j)

{if(rear == maxSize-1)

rear = -1;

queArray[++rear] = j;

nItems++;}

8/8/2019 M6-Queue

51/53

Method remove()

public int remove()

{

int temp = queArray[front++];if(front == maxSize)

front = 0;

nItems--;

return temp;}

8/8/2019 M6-Queue

52/53

Method main()

public static void main(String[] args){

CircularQueue theQueue = new CircularQueue(5); // queue holds 5 items

System.out.println("front : " + theQueue.front + "rear : " + theQueue.rear);

theQueue.insert(10); theQueue.insert(20);

theQueue.insert(30); theQueue.insert(40);

theQueue.remove();System.out.println(remove 1x, front : " +theQueue.front +" rear : " +theQueue.rear);

theQueue.insert(50);

theQueue.insert(60);

System.out.println("add 2 elemen, front : " +theQueue.front+"rear:+theQueue.rear);

theQueue.remove();

System.out.println(remove 1x, front : " +theQueue.front+ rear : " +theQueue.rear);while( !theQueue.isEmpty() )

{

int n = theQueue.remove();

System.out.print(n);

System.out.print(" ");

}

8/8/2019 M6-Queue

53/53

Pustaka

Sartaj Sahni, Presentation L5 & L10

Jokonowo, Bambang S.Si, Pemrograman Berorientasi Obyek,

Pusat pengembangan bahan ajar UMB, 2006.

Noviyanto, P

emrograman Berorientasi Obyek (P

BO) Array,2005

Nugroho, Adi, Algoritma dan Struktur Data Dalam Bahasa

Java, ANDI Yogyakarta, 2008.

Michaell Waite, Data Structures and Algorithms in Java,

SAMS, 2001