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#1 purplesmiles  Icon User is offline

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RemoveAll Function

Posted 02 October 2012 - 08:15 PM

I've written the code for the RemoveAll Function. It works. However, it crashes before completely displaying the outcome and it adds a bunch of random numbers to the end. I can go back up to the top of the program and see that it has output the correct list of numbers, but then it has added a really really long list of random numbers. I can't figure out what is wrong with it. For the problem, I'm only supposed to be coding the RemoveAll Function so that is all I can change.

#ifndef H_arrayListType
#define H_arrayListType

#include <iostream>
#include <cassert>

using namespace std;

template <class elemType>
class arrayListType
{
public:
    const arrayListType<elemType>& 
operator=(const arrayListType<elemType>&);
		//Overloads the assignment operator

    bool isEmpty();
		//Function to determine whether the list is empty
		
    bool isFull();
		//Function to determine whether the list is full
		
    int listSize();
		//Function to determine the number of elements in the list
		
    int maxListSize();
		//Function to determine the size of the list
 	
    void print() const;
		//Function to output the elements of the list
		
    bool isItemAtEqual(int location, const elemType& item);
		//Function to determine whether the item is the same 
 		//as the item in the list at the position specified by
		
   void insertAt(int location, const elemType& insertItem);
		//Function to insert an item in the list at the 
		//position specified by location. The item to be inserted 
		//is passed as a parameter to the function.
		   
   void insertEnd(const elemType& insertItem);
		//Function to insert an item at the end of the list 
		//The parameter insertItem specifies the item to be 
		//inserted.
		
    void removeAt(int location);
		//Function to remove the item from the list at the 
		//position specified by location 
		
    void retrieveAt(int location, elemType& retItem);
		//Function to retrieve the element from the list at the  
		//position specified by location 
		
    void replaceAt(int location, const elemType& repItem);
		//Function to replace the elements in the list at the 
		//position specified by location. The item to be replaced 
		//is specified by the parameter repItem.
		
    void clearList();
		
 		
    int seqSearch(const elemType& item);
  		
		
    void insert(const elemType& insertItem);
		
		
    void remove(const elemType& removeItem);
		
	
	
	void removeAll(const elemType& removeItem);
		
		

    arrayListType(int size = 100);
		
		

    arrayListType(const arrayListType<elemType>& otherList); 
		//copy constructor

    ~arrayListType();
		//destructor
		//Deallocates the memory occupied by the array.

protected:
    elemType *list; 	//array to hold the list elements
    int length;		//to store the length of the list
    int maxSize;		//to store the maximum size of the list
};



template <class elemType>
bool arrayListType<elemType>::isEmpty()
{
	return (length == 0);
}

template <class elemType>
bool arrayListType<elemType>::isFull()
{
	return (length == maxSize);
}

template <class elemType>
int arrayListType<elemType>::listSize()
{
	return length;
}

template <class elemType>
int arrayListType<elemType>::maxListSize()
{
	return maxSize;
}

template <class elemType>
void arrayListType<elemType>::print() const
{
	for(int i = 0; i < length; i++)
		cout<<list[i]<<" ";
	cout<<endl;
}

template <class elemType>
bool arrayListType<elemType>::isItemAtEqual
                   (int location, const elemType& item)
{
	return(list[location] == item);
}

template <class elemType>
void arrayListType<elemType>::insertAt
                   (int location, const elemType& insertItem)
{
	if(location < 0 || location >= maxSize)
		cerr<<"The position of the item to be inserted "
			<<"is out of range."<<endl;
	else
		if(length >= maxSize)  //list is full
			cerr<<"Cannot insert in a full list."<<endl;
		else
		{
			for(int i = length; i > location; i--)
				list[i] = list[i - 1];	//move the elements down

			list[location] = insertItem;	//insert the item at the 
 										//specified position

			length++;	//increment the length
		}
} //end insertAt

template <class elemType>
void arrayListType<elemType>::insertEnd(const elemType& insertItem)
{
	if(length >= maxSize)  //the list is full
		cerr<<"Cannot insert in a full list."<<endl;
	else
	{
		list[length] = insertItem;	//insert the item at the end
		length++;	//increment length
	}
} //end insertEnd

template <class elemType>
void arrayListType<elemType>::removeAt(int location)
{
	if(location < 0 || location >= length)
    	cerr<<"The location of the item to be removed "
			<<"is out of range."<<endl;
	else
	{
   		for(int i = location; i < length - 1; i++)
	 		list[i] = list[i+1];

		length--;
	}
} //end removeAt

template <class elemType>
void arrayListType<elemType>::retrieveAt
                     (int location, elemType& retItem)
{
	if(location < 0 || location >= length)
    	cerr<<"The location of the item to be retrieved is "
			<<"out of range."<<endl;
	else
		retItem = list[location];
} // retrieveAt

template <class elemType>
void arrayListType<elemType>::replaceAt
                    (int location, const elemType& repItem)
{
	if(location < 0 || location >= length)
    	cerr<<"The location of the item to be replaced is "
			<<"out of range."<<endl;
	else
		list[location] = repItem;

} //end replaceAt

template <class elemType>
void arrayListType<elemType>::clearList()
{
	length = 0;
} // end clearList

template <class elemType>
int arrayListType<elemType>::seqSearch(const elemType& item)
{
	int loc;
	bool found = false;

	for(loc = 0; loc < length; loc++)
	   if(list[loc] == item)
	   {
		found = true;
		break;
	   }

	if(found)
		return loc;
	else
		return -1;
} //end seqSearch

template <class elemType>
void arrayListType<elemType>::insert(const elemType& insertItem)
{
	int loc;

	if(length == 0)					 //list is empty
		list[length++] = insertItem; //insert the item and 
 									 //increment the length
	else
		if(length == maxSize)
			cerr<<"Cannot insert in a full list."<<endl;
		else
		{
			loc = seqSearch(insertItem);

			if(loc == -1)   //the item to be inserted 
							//does not exist in the list
				list[length++] = insertItem;
			else
				cerr<<"the item to be inserted is already in "
 					<<"the list. No duplicates are allowed."<<endl;
	}
} //end insert

template <class elemType>
void arrayListType<elemType>::remove(const elemType& removeItem)
{
	int loc;

	if(length == 0)
		cerr<<"Cannot delete from an empty list."<<endl;
	else
	{
		loc = seqSearch(removeItem);

		if(loc != -1)
			removeAt(loc);
		else
			cout<<"The item to be deleted is not in the list."
				<<endl;
	}

} //end remove

template <class elemType>
void arrayListType<elemType>::removeAll(const elemType& removeItem)
{

   	int loc;
    int number;
      
    for (loc=0; loc<number; loc++)
        if (list[loc]!=removeItem)
       cout<<list[loc]<<"";
    
      
} //end removeAll

template <class elemType>
arrayListType<elemType>::arrayListType(int size)
{
	if(size < 0)
	{
		cerr<<"The array size must be positive. Creating "
 			<<"an array of size 100. "<<endl;

 	   maxSize = 100;
 	}
 	else
 	   maxSize = size;

	length = 0;

	list = new elemType[maxSize];
	assert(list != NULL);
}

template <class elemType>
arrayListType<elemType>::~arrayListType()
{
	delete [] list;
}

	//copy constructor
template <class elemType>
arrayListType<elemType>::arrayListType
                   (const arrayListType<elemType>& otherList)
{
   maxSize = otherList.maxSize;
   length = otherList.length;
   list = new elemType[maxSize]; 	//create the array
   assert(list != NULL);	//terminate if unable to allocate
 							//memory space

   for(int j = 0; j < length; j++)  //copy otherList
      list [j] = otherList.list[j];
}//end copy constructor


template <class elemType>
const arrayListType<elemType>& arrayListType<elemType>::operator=
			(const arrayListType<elemType>& otherList)
{
	if(this != &otherList)	//avoid self-assignment
	{				   
	   delete [] list;				   
	   maxSize = otherList.maxSize;		   
       length = otherList.length;			   
	  
       list = new elemType[maxSize];		   
	   assert(list != NULL);			   

	    
	   for(int i = 0; i < length; i++)	   
	       list[i] = otherList.list[i];	   
	}

    return *this;					   	   
}


#endif 




and here is the other file

#include <iostream>

#include "arrayListType.h"

using namespace std;

int main()
{
    arrayListType<int> intList(100);			 			
   
    int counter;											
    int number;												

    cout<<"List 5: Processing the integer list"
		<<endl;												
    cout<<"List 6: Enter 10 integers: ";						
										
    for(counter = 0; counter < 10; counter++)				
    {	
		cin>>number;						 				
		intList.insertAt(counter, number);		 			
    }

    cout<<endl;												
    cout<<"List 11: The list you entered is: ";				
    intList.print();										
    cout<<endl;												

    cout<<"Line 14: Enter the item to be deleted: ";		
    cin>>number;											
    intList.removeAll(number);									
    cout<<"Line 17: After removing "<<number
		<<", the list is:"<<endl;							
    intList.print();										
    cout<<endl;		
    
    										
    system("pause");
    return 0;
}



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Replies To: RemoveAll Function

#2 Skydiver  Icon User is offline

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Re: RemoveAll Function

Posted 02 October 2012 - 08:30 PM

You removeAll() does not remove anything.
template <class elemType>
void arrayListType<elemType>::removeAll(const elemType& removeItem)
{

   	int loc;
    int number;
      
    for (loc=0; loc<number; loc++)
        if (list[loc]!=removeItem)
       cout<<list[loc]<<"";
    
      
} //end removeAll



The random numbers you are seeing are because number on line 6 is not initialized. So the loop just goes on until loc is equal to whatever random number happens to be stored in number. Basically, you are indexing way past your array.

And as I said before, you aren't removing anything from the array list. All you've done is print out the contents of the array and skipped over the values that were intended to be removed. When your print() method gets called, you'll see that the values are still there.
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#3 purplesmiles  Icon User is offline

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Re: RemoveAll Function

Posted 02 October 2012 - 08:42 PM

Thank you so much! I've finally figured it out. It only took me 6 hours lol
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