97 lines
2.5 KiB
C++
97 lines
2.5 KiB
C++
QueueAr.cpp - Implementation for queue - array version
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#include "QueueAr.h"
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/**
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* Construct the queue.
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*/
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template <class Object>
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Queue<Object>::Queue( int capacity ) : theArray( capacity )
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{
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makeEmpty( );
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}
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/**
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* Test if the queue is logically empty.
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* Return true if empty, false otherwise.
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*/
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template <class Object>
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bool Queue<Object>::isEmpty( ) const
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{
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return currentSize == 0;
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}
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/**
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* Test if the queue is logically full.
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* Return true if full, false otherwise.
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*/
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template <class Object>
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bool Queue<Object>::isFull( ) const
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{
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return currentSize == theArray.size( );
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}
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/**
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* Make the queue logically empty.
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*/
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template <class Object>
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void Queue<Object>::makeEmpty( )
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{
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currentSize = 0;
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front = 0;
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back = -1;
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}
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/**
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* Get the least recently inserted item in the queue.
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* Return the least recently inserted item in the queue
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* or throw Underflow if empty.
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*/
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template <class Object>
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const Object & Queue<Object>::getFront( ) const
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{
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if( isEmpty( ) )
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throw Underflow( );
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return theArray[ front ];
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}
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/**
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* Return and remove the least recently inserted item from the queue.
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* Throw Underflow if empty.
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*/
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template <class Object>
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Object Queue<Object>::dequeue( )
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{
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if( isEmpty( ) )
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throw Underflow( );
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currentSize--;
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Object frontItem = theArray[ front ];
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increment( front );
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return frontItem;
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}
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/**
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* Insert x into the queue.
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* Throw Overflow if queue is full
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*/
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template <class Object>
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void Queue<Object>::enqueue( const Object & x )
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{
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if( isFull( ) )
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throw Overflow( );
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increment( back );
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theArray[ back ] = x;
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currentSize++;
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}
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/**
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* Internal method to increment x with wraparound.
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*/
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template <class Object>
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void Queue<Object>::increment( int & x )
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{
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if( ++x == theArray.size( ) )
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x = 0;
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}
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