/*********************************************
Filename:		queue.cpp
Developer:		Jay Suttiruttana
Dev Platform:		MS Windows 98
Compiler:		MS Visual C++ (v6.0)
Purpose:		To illustrated queue algorithm
**********************************************/

#include <iostream.h>
#include <stdio.h>		//for getchar()

struct Queue
{
	char Data;
	Queue *linkPtr;
};

Queue *enque(Queue *quePtr, char queData);
Queue *deque(Queue *quePtr);

void dumpQueue(Queue *quePtr);

void main()
{
	Queue *NodePtr;
	char inData;

	NodePtr = NULL;
	
	//Entering data ($ to exit) into queue	
	while(inData != '$')
	{
		inData = getchar();
		NodePtr = enque(NodePtr, inData);
	}
	
	//Deque
	if(NodePtr != NULL)
	{	
		cout<<endl<<"Deque: "<<endl;
		dumpQueue(NodePtr);
	}

	cout<<endl;
}

Queue *enque(Queue *quePtr, char queData)
{
	Queue *lPtr = quePtr;

	if(quePtr != NULL)
	{
		while(quePtr->linkPtr != NULL)
			quePtr = quePtr->linkPtr;
		
		quePtr->linkPtr = new Queue;
		quePtr=quePtr->linkPtr;
		quePtr->linkPtr = NULL;
		quePtr->Data = queData;
		return lPtr;
	}

	else
	{
		quePtr= new Queue;
		quePtr->linkPtr = NULL;
		quePtr->Data = queData;
		return quePtr;
	}
}

Queue *deque(Queue *quePtr)
{
	Queue *tempPtr;

	cout<<quePtr->Data;
	tempPtr = quePtr->linkPtr;
	delete quePtr;
	return tempPtr;
}

void dumpQueue(Queue *quePtr)
{
	while(quePtr != NULL)
		quePtr = deque(quePtr);
}