copy a stack to another instance?

Question

drunkenmonk 0 Newbie Poster

14 Years Ago

I am writing a program to manipulate a stack containing integers using push, pop, print, etc. The only thing I have left is to write a function called copy. Here is what I've tried so far:

void Stack::Copy(Stack otherStack)
		{

			otherStack.top = top;
							
			for (int ii = top-1; ii >= 0; ii--) 
                       {
				otherStack.Push(elements[ii]);

		       }
                }

and this:

void Stack::Copy(Stack otherStack)
		{

			otherStack.top = top;
							
			for (int ii = top-1; ii >= 0; ii--) {
				otherStack.elements[ii] = elements[ii];
		}
		
		}

Any help would be appreciated!

thanks

c++

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10 Replies
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Latest Post 14 Years Ago Latest Post by drunkenmonk

All 10 Replies

ArkM 1,090 Postaholic

14 Years Ago

1. Use code tag with the language specifier:
[code=cpluplus] source

[/code]
2. We can't help you (mor precisely, we can't verify your solution) without class Stack definition. However I see that your Copy member signature is wrong. You never modify passed by value parameter. If you want to copy from *this to otherStack, use a reference to otherStack:

void Stack::Copy(Stack& otherStack);

3. Better try to overload Stack::operator=() and define copy constructor for this class. Essentially it's the same code as for Copy member.

Sky Diploma 571 Practically a Posting Shark

14 Years Ago

On the other note, Would Elements or Top be accessible if they are private?

Sky Diploma 571 Practically a Posting Shark

14 Years Ago

I am writing a program to manipulate a stack containing integers using push, pop, print, etc. The only thing I have left is to write a function called copy. Here is what I've tried so far:
void Stack::Copy(Stack otherStack)
		{

			otherStack.top = top;
							
			for (int ii = top-1; ii >= 0; ii--) 
                       {
				otherStack.Push(elements[ii]);

		       }
                }
and this:
void Stack::Copy(Stack otherStack)
		{

			otherStack.top = top;
							
			for (int ii = top-1; ii >= 0; ii--) {
				otherStack.elements[ii] = elements[ii];
		}
		
		}
Any help would be appreciated!
thanks

Why are you copying the stack in reverse?
Though it doesnt matter :) in the second function
And Are you getting an error during compilation?

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drunkenmonk 0 Newbie Poster · Answer 1 · 2009-05-11T13:02:12+00:00

here is all I have so far:

Project.cpp:

//					 
//
//=================
#include "stdafx.h"
#include <iostream>
#include <string>
//===============

//================
#include "Stack.h"
//================

//==================
using namespace std;
//==================

//  ============
//  Enumerations
//  ===========================================
	enum menuSelections {Push, Pop, Initialize,
						 Print, Purge, Sum, Average, Roll, Copy};
//  ===================================

//  ===================
//  Function Prototypes
//  ==========================
	void GetAnswer( string& );
	void Finished( string, bool& );
    void Menu( menuSelections& );
	void ProcessCommandA( menuSelections,
				         Stack& );
	void ProcessCommandB( menuSelections,
						 Stack& );
//	==============================

//  ===========
    int main( )
    {
//	=====================
//	Variable Declarations
//	=============================
	menuSelections menuSelection;


    bool   finished = false;
	string userAnswer;
	char stackChoice;


    Stack stackA;
	Stack stackB;
//	====================

//	========================================
//	Welcome Banner and Instructions for User
//	=========================================================
	cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+" << endl;
	cout << "+                             +" << endl;
	cout << "= WELCOME TO THE STACK TESTER =" << endl;
	cout << "+                             +" << endl;
	cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=" << endl;
	cout << endl << endl;

	cout << "THIS PROGRAM ALLOWS THE USER TO CREATE" << endl;
	cout << "AND MANIPULATE A STACK WHOSE VALUES ARE" << endl;
	cout << "HELD BY A STATIC ARRAY." << endl;
	cout << "=+=+=+=+=+=+=+=+=+=+=+=" << endl;
	cout << endl << endl;
//	=====================

//		=========
//		User Loop
//		===================
		while ( !finished ) 
		{
			Menu( menuSelection );



			cout << "Which Stack?(a/b)" << endl;
			cin >> stackChoice;


			if (stackChoice == 'a')
				ProcessCommandA( menuSelection,
								stackA);
			else if (stackChoice == 'b')

			ProcessCommandB( menuSelection,
							stackB );
			else
			{
				cout << "Bad Choice, try again:" << endl;
			cin >> stackChoice;
			}


//			===========================
//			User loop termination code.
//			========================
			GetAnswer( userAnswer );
			Finished( userAnswer, finished );
//			=================================

		} // while loop
//		===============


	return 0;
}//End Function Main
//==================


//	==================
//	Function GetAnswer
//	==============================
	void GetAnswer( string& answer )
	{
	bool validAnswer = false;
		while ( !validAnswer ) 
		{
		    cout << "Would you like to modify one of the stacks again? (y or n)" 
			     << endl;
		    cin >> answer;

		    if (( answer.length() == 1 ) && 
			  (( answer[0] == 'y' ) || ( answer[0] == 'n' )))
				    validAnswer = true;
		
			else
				cout << "Invalide choice. Please enter (y or n)"
				     << endl;
		}			
	}//End Function GetAnswer
//	=========================

//  =================
//  Function Finished
//  =============================
	void Finished( string answer,
		           bool&  finished )
	{
		if (answer[0] == 'n')
			finished = true;
	}//End Function Finished
//	========================


//  =============
//  Function Menu
//  ==============================================
	void Menu( menuSelections& userMenuSelection )
	{
		int selectionNumber = 1;

		cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+" << endl;
		cout << "MENU FOR TESTING THE STACK" << endl;
		cout << endl;
		cout << "1: Push" << endl;
		cout << "2: Pop" << endl;
		cout << "3: Initialize Stack" << endl;
		cout << "4: Print Stack" << endl;
		cout << "5: Purge Stack" << endl;
		cout << "6: Sum of Stack" << endl;
		cout << "7: Average of Stack" << endl;
		cout << "8: Roll Top Two Elements" << endl;
		cout << "9: Copy stack to other instance" << endl;

		cout << endl;

		cout << "What is your selection?" << endl;
        cin >> selectionNumber;

		switch ( selectionNumber )
		{
		    case 1: userMenuSelection = Push;
				break;
		    case 2: userMenuSelection = Pop;
				break;
		    case 3: userMenuSelection = Initialize;
				break;
		    case 4: userMenuSelection = Print;
				break;
		    case 5: userMenuSelection = Purge;
				break;
			case 6: userMenuSelection = Sum;
				break;
			case 7: userMenuSelection = Average;
				break;
			case 8: userMenuSelection = Roll;
				break;
			case 9: userMenuSelection = Copy;
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "The selection is being set to 4: Print." << endl;
			        userMenuSelection = Print;					
				break;
		}

	}//End Function Menu
//	====================


//  ========================
//  Function ProcessCommandA
//  ======================================================
	void ProcessCommandA( menuSelections userMenuSelection,
				         Stack& stackA )
	{
		Stack stackB;
		int integerValue;
		int sum;
		switch( userMenuSelection )
		{
		    case Push:
				     cout << "Enter a value to add to the list." << endl;
				     cin >> integerValue;
				 stackA.Push(integerValue);
				break;
			case Pop: stackA.Pop(integerValue);
				break;
			case Initialize: stackA.InitializeStack( );
				break;
		    case Print: stackA.PrintStack( );
				break;
		    case Purge: stackA.PurgeStack( );
				break;
			case Sum: stackA.SumOfElements( sum );
				break;
			case Average: stackA.Average( );
				break;
			case Roll: stackA.Roll( );
				break;
			case Copy: stackA.Copy(  stackB );
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "Print member-function invoked." << endl;
			        stackA.PrintStack();				
				break;
		}

	}//End Function ProcessCommandA
//	===============================


//  ========================
//  Function ProcessCommandA
//  ======================================================
	void ProcessCommandB( menuSelections userMenuSelection,
				         Stack& stackB )
	{
		Stack stackA;
		int integerValue;
		int sum;
		switch( userMenuSelection )
		{
		    case Push:
				     cout << "Enter a value to add to the list." << endl;
				     cin >> integerValue;
				 stackB.Push(integerValue);
				break;
			case Pop: stackB.Pop(integerValue);
				break;
			case Initialize: stackB.InitializeStack( );
				break;
		    case Print: stackB.PrintStack( );
				break;
		    case Purge: stackB.PurgeStack( );
				break;
			case Sum: stackB.SumOfElements( sum );
				break;
			case Average: stackB.Average( );
				break;
			case Roll: stackB.Roll( );
				break;
			case Copy: stackB.Copy(  stackA );
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "Print member-function invoked." << endl;
			        stackB.PrintStack();				
				break;
		}

	}//End Function ProcessCommandB
//	===============================

Stack.h:

//=======
//Stack.h
//=======
//    |
//  \ |	/
//   \|/
//	  V
//  ===========
   #pragma once
//  ===========

//  ===========
    class Stack
    {
//      =========
//      Constants
//		======================================
        const static int MAX_STACK_SIZE = 200;
		//      ======================================

//		=======
        public:
//		=======

//			============
//			Constructors
//			=============
	        Stack(void);
//			============

//			==========
//			Destructor
//			============
	       ~Stack(void);
//          ============

//          ================
//			Member Functions
//          ==========================
            void Stack::PurgeStack( );
            void Stack::InitializeStack( );
            void Stack::Pop( int& );
	        void Stack::PrintStack( );
            void Stack::Push( int );
            bool Stack::StackEmpty( );
            bool Stack::StackFull( );
			int Stack::SumOfElements(int& );
			void Stack::Average( );
			void Stack::Roll( );
			void Stack::Copy( Stack& );
//          =========================

//		========
	    private:
//		========

//          ================
//          Member variables
//          ========
	        int top;
	        int elements[MAX_STACK_SIZE];
//          =============================

    }; // Class Stack
//  =================

//===========
//End Stack.h
//===========

Stack.cpp:

//=========
//Stack.cpp
//=========
//    |
//  \ |	/
//   \|/
//	  V
//=================
#include "StdAfx.h"
#include <iostream>
#include <iomanip>
//=================

#include "Stack.h"
//================

//==================
using namespace std;
//==================

//  ============
//  Constructors
//  ============
        
//      ===================
//      Default Constructor
//		==================== 
        Stack::Stack( void )
        {
			PurgeStack();
        } //End Constructor
//		===================

//  ==========
//  Destructor
//	=====================
    Stack::~Stack( void )
    {

    } //End Destructor
//	==================

//  ================
//  Member-Functions
//  ================
        
//      ===================
//		Function PurgeStack
//      =========================
        void Stack::PurgeStack( )
        {
            for (int ii = 0; ii < MAX_STACK_SIZE; ii++)
			{
                elements[ii] = 0;
	        } 
	        top = 0;
        }//End Function PurgeStack
//      ==========================

//      ========================
//		Function InitializeStack
//		==============================
        void Stack::InitializeStack( )
        {
            top = 0;
        }//End Function InitializeStack
//      ===============================

//      ============
//		Function Pop
//      ===================================
        void Stack::Pop( int& poppedValue )
        {
			if (!StackEmpty()){
	        top--;
            poppedValue = elements[top];
			PrintStack();
		}
			else
			PrintStack();
        } // Member-Function Pop
//      ========================

//      ===================
//      Function PrintStack
//      =========================      
	    void Stack::PrintStack( )
        {
			cout << endl << endl;
            cout << "+ Top of Stack  +" << endl;
			cout << "=+=+=+=+=+=+=+=+=" << endl;
			cout << endl;
            if ( StackEmpty() )
                cout << "The stack is empty." << endl;
            else{
                for ( int ii = top - 1; ii >= 0; ii-- ){
                    cout << "At index[" << ii << "] = "
                         << elements[ii] << endl;
                } // for
            } // else
			cout << endl;
			cout << "=+=+=+=+=+=+=+=+=" << endl;
            cout << "+Bottom of Stack+" << endl << endl;
        }//End Function PrintStack
//      ==========================

//      =============
//		Function Push
//		===================================
        void Stack::Push( int pushedValue ) 
        {
            elements[top] = pushedValue;
            top++;
			PrintStack();
        }//End Function Push
//      =========================

//      ===================
//		Function StackEmpty
//      =========================
        bool Stack::StackEmpty( )
        {
            return (top == 0);
        }//End Function StackEmpty
//      ==========================

//      ==================
//		Function StackFull
//      ========================
        bool Stack::StackFull( )
        {
            return (top == MAX_STACK_SIZE);
        }//End Function StackFull
//      =========================

//      ======================
//		Function SumOfElements
//      ==================================
		int Stack::SumOfElements(int& sum)
		{
			sum = 0;
			for (int ii = 0; ii <= (top-1);ii++)
				sum = sum + elements[ii];
			cout << "Sum = " << sum << endl;
			return sum;
		}//End SumOfElements
//		====================

//      ================
//		Function Average
//      ======================
		void Stack::Average( )
		{
			cout << fixed << showpoint << setprecision(2);

			int sum;
			double result = 0;
			cout << endl;
			SumOfElements( sum );
			cout << endl;
			double total = sum;
			double divisor = top;

			if (sum == 0)
				cout << "Average = 0, the stack is empty" << endl << endl;
			else
			{
			result = total/ divisor;
			cout << "Average = " << result << endl << endl;
			}
		}

		void Stack::Roll( )
		{
			if (top == 0)
				cout << "Stack is empty, There are no elements to roll" << endl << endl;
			else if (top == 1)
				cout << "There is only one element in the stack, nothing to roll with" << endl << endl;
			else
			{
			int temp;
			temp = elements[top-1];
			elements[top-1] = elements[top-2];
			elements[top-2] = temp;
			PrintStack( );
			}
		}

		  void Stack::Copy( Stack& otherStack)
		{
			 otherStack.top = top;


			for ( int ii = top-1; ii >=0 ; ii--){

			otherStack.Push(elements[ii]);
			}
	

		
		}





//  ====================
//  End Member-Functions
//  =====================

//=============
//End Stack.cpp
//=============

drunkenmonk 0 Newbie Poster · Answer 2 · 2009-05-11T13:22:19+00:00

no errors, and I have tried both ways, I've tried every way even if it sounded crazy, I am stumped.

Sky Diploma 571 Practically a Posting Shark · Answer 3 · 2009-05-11T13:44:01+00:00

void Stack::Copy(Stack otherStack)
		{

			otherStack.top = top;
							
			for (int ii = top-1; ii >= 0; ii--) 
                       {
				otherStack.Push(elements[ii]);

		       }
                }

I found an error in your code

When you use push(element)
Why did you assign OtherStack.top=top;
That way you assign variables above the current stack size.

For example

Stack size =10;
so top =10;
when push(element );
is called.
then what we have is elements[top]=element //Which is actually 10;
Then 10++ is 11

Though my explaination is a little rough i hope you get the point

drunkenmonk 0 Newbie Poster · Answer 4 · 2009-05-11T14:23:44+00:00

That was just the latest incarnation I've tried. I cannot figure out why either:
Push(otherStack.elements[ii]);
or
otherStack.Push(elements[ii]);
or
elements[ii] = otherStack.elements[ii];
or
otherStack.elements[ii] = elements[ii];

will not work...
am I missing something here?

Sky Diploma 571 Practically a Posting Shark · Answer 5 · 2009-05-11T14:51:42+00:00

void Stack::Copy( Stack& otherStack)
		{
			 
			for ( int ii = 0; ii <=top-1 ; ii++){

			otherStack.Push(elements[ii]);
			}
	

		
		}

I have tried your code. and it executed. The only mistake that you have made was that you have defined stack A while working with Stack B and vice versa locally. So all the info is gone after that function is executed.

//					 
//
//=================
#include "stdafx.h"
#include <iostream>
#include <string>
//===============

//================
#include "Stack.h"
//================

//==================
using namespace std;
//==================

//  ============
//  Enumerations
//  ===========================================
	enum menuSelections {Push, Pop, Initialize,
						 Print, Purge, Sum, Average, Roll, Copy};
//  ===================================

//  ===================
//  Function Prototypes
//  ==========================
	void GetAnswer( string& );
	void Finished( string, bool& );
    void Menu( menuSelections& );
	void ProcessCommandA( menuSelections,
				         Stack& );
	void ProcessCommandB( menuSelections,
						 Stack& );
//	==============================

//  ===========
    int main( )
    {
//	=====================
//	Variable Declarations
//	=============================
	menuSelections menuSelection;


    bool   finished = false;
	string userAnswer;
	char stackChoice;


    Stack stackA;
	Stack stackB;
//	====================

//	========================================
//	Welcome Banner and Instructions for User
//	=========================================================
	cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+" << endl;
	cout << "+                             +" << endl;
	cout << "= WELCOME TO THE STACK TESTER =" << endl;
	cout << "+                             +" << endl;
	cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=" << endl;
	cout << endl << endl;

	cout << "THIS PROGRAM ALLOWS THE USER TO CREATE" << endl;
	cout << "AND MANIPULATE A STACK WHOSE VALUES ARE" << endl;
	cout << "HELD BY A STATIC ARRAY." << endl;
	cout << "=+=+=+=+=+=+=+=+=+=+=+=" << endl;
	cout << endl << endl;
//	=====================

//		=========
//		User Loop
//		===================
		while ( !finished ) 
		{
			Menu( menuSelection );



			cout << "Which Stack?(a/b)" << endl;
			cin >> stackChoice;


			if (stackChoice == 'a')
				ProcessCommandA( menuSelection,
								stackA);
			else if (stackChoice == 'b')

			ProcessCommandB( menuSelection,
							stackB );
			else
			{
				cout << "Bad Choice, try again:" << endl;
			cin >> stackChoice;
			}


//			===========================
//			User loop termination code.
//			========================
			GetAnswer( userAnswer );
			Finished( userAnswer, finished );
//			=================================

		} // while loop
//		===============


	return 0;
}//End Function Main
//==================


//	==================
//	Function GetAnswer
//	==============================
	void GetAnswer( string& answer )
	{
	bool validAnswer = false;
		while ( !validAnswer ) 
		{
		    cout << "Would you like to modify one of the stacks again? (y or n)" 
			     << endl;
		    cin >> answer;

		    if (( answer.length() == 1 ) && 
			  (( answer[0] == 'y' ) || ( answer[0] == 'n' )))
				    validAnswer = true;
		
			else
				cout << "Invalide choice. Please enter (y or n)"
				     << endl;
		}			
	}//End Function GetAnswer
//	=========================

//  =================
//  Function Finished
//  =============================
	void Finished( string answer,
		           bool&  finished )
	{
		if (answer[0] == 'n')
			finished = true;
	}//End Function Finished
//	========================


//  =============
//  Function Menu
//  ==============================================
	void Menu( menuSelections& userMenuSelection )
	{
		int selectionNumber = 1;

		cout << "=+=+=+=+=+=+=+=+=+=+=+=+=+" << endl;
		cout << "MENU FOR TESTING THE STACK" << endl;
		cout << endl;
		cout << "1: Push" << endl;
		cout << "2: Pop" << endl;
		cout << "3: Initialize Stack" << endl;
		cout << "4: Print Stack" << endl;
		cout << "5: Purge Stack" << endl;
		cout << "6: Sum of Stack" << endl;
		cout << "7: Average of Stack" << endl;
		cout << "8: Roll Top Two Elements" << endl;
		cout << "9: Copy stack to other instance" << endl;

		cout << endl;

		cout << "What is your selection?" << endl;
        cin >> selectionNumber;

		switch ( selectionNumber )
		{
		    case 1: userMenuSelection = Push;
				break;
		    case 2: userMenuSelection = Pop;
				break;
		    case 3: userMenuSelection = Initialize;
				break;
		    case 4: userMenuSelection = Print;
				break;
		    case 5: userMenuSelection = Purge;
				break;
			case 6: userMenuSelection = Sum;
				break;
			case 7: userMenuSelection = Average;
				break;
			case 8: userMenuSelection = Roll;
				break;
			case 9: userMenuSelection = Copy;
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "The selection is being set to 4: Print." << endl;
			        userMenuSelection = Print;					
				break;
		}

	}//End Function Menu
//	====================


//  ========================
//  Function ProcessCommandA
//  ======================================================
	void ProcessCommandA( menuSelections userMenuSelection,
				         Stack& stackA )
	{
		Stack stackB;
		int integerValue;
		int sum;
		switch( userMenuSelection )
		{
		    case Push:
				     cout << "Enter a value to add to the list." << endl;
				     cin >> integerValue;
				 stackA.Push(integerValue);
				break;
			case Pop: stackA.Pop(integerValue);
				break;
			case Initialize: stackA.InitializeStack( );
				break;
		    case Print: stackA.PrintStack( );
				break;
		    case Purge: stackA.PurgeStack( );
				break;
			case Sum: stackA.SumOfElements( sum );
				break;
			case Average: stackA.Average( );
				break;
			case Roll: stackA.Roll( );
				break;
			case Copy: stackA.Copy(  stackB );
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "Print member-function invoked." << endl;
			        stackA.PrintStack();				
				break;
		}

	}//End Function ProcessCommandA
//	===============================


//  ========================
//  Function ProcessCommandA
//  ======================================================
	void ProcessCommandB( menuSelections userMenuSelection,
				         Stack& stackB )
	{
		Stack stackA;
		int integerValue;
		int sum;
		switch( userMenuSelection )
		{
		    case Push:
				     cout << "Enter a value to add to the list." << endl;
				     cin >> integerValue;
				 stackB.Push(integerValue);
				break;
			case Pop: stackB.Pop(integerValue);
				break;
			case Initialize: stackB.InitializeStack( );
				break;
		    case Print: stackB.PrintStack( );
				break;
		    case Purge: stackB.PurgeStack( );
				break;
			case Sum: stackB.SumOfElements( sum );
				break;
			case Average: stackB.Average( );
				break;
			case Roll: stackB.Roll( );
				break;
			case Copy: stackB.Copy(  stackA );
				break;
		    default: 
			        cout << "Invalid selection." << endl;
			        cout << "Print member-function invoked." << endl;
			        stackB.PrintStack();				
				break;
		}

	}//End Function ProcessCommandB
//	===============================

I think you should remove those declarations over there and declare them globally and the program will run fine.

drunkenmonk 0 Newbie Poster · Answer 6 · 2009-05-11T15:01:06+00:00

I see where thats a problem, but when I remove them I get these errors:

Error 2 error C2065: 'stackA' : undeclared identifier
Error 1 error C2065: 'stackB' : undeclared identifier

Thanks

drunkenmonk 0 Newbie Poster · Answer 7 · 2009-05-11T15:03:20+00:00

Sorry I didn't see 'declare globally' My mistake

thanks so much.

copy a stack to another instance?

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