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class LinkEntry {

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private Object element;

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private LinkEntry link;

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public LinkEntry (Object element, LinkEntry link) (

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this.element = element;

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this.link = link;

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}

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public Object getElement () { return element; )

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public LinkEntry getlink () { return link; )

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public void setlink (LinkEntry newLink) { link = newLink; )

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}

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public class Queue {

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private LinkEntry front;

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private LinkEntry rear;

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private int count;

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public Queue; () {

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front = null;

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rear = null;

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count = 0;

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}

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public void arrive (Object element) {

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LinkEntry entry = new LinkEntry(element, null) ;

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if (front == null) {

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front = Entry;

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} else {

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rear.setLink (entry);

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}

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rear = entry;

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count++;

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}

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Object leave () {

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Object element = front.getElement () ;

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front = front.getLink() ;

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count--;

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return element;

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}

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Object peek() { return front.getElement () ;

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int length () { return count; }

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boolean empty () { return count == 0; )

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boolean full () {

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LinkEntry entry = new LinkEntry(null, null) ;

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return entry == null;

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}

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}