I'm studying for one of my exam's and this is my first c++ class and my professor gave one of these questions for our study guide... and I'm having trouble with it. And since our final is open book and open notes he's not giving us the answers, and i've check on the internet and my book and theres nothing thats helping me :-(

The following code is for the header file, i have to make a cpp file and with this make a sorting function and in the cpp file and for the user to pick a random 10 numbers and to make them in order. Using the linkedListType class I have to add a selection sort function for linked lists. Then i have to write a program that tests the selection sort function.

#ifndef H_LinkedListType
#define H_LinkedListType
 
#include <iostream>
#include <cassert>
using namespace std;
 
template <class Type>
struct nodeType
{
	Type info;
	nodeType<Type> *link;
};
 
template<class Type>
class linkedListType
{
	template<class Type>
	friend ostream& operator<<(ostream&, const linkedListType<Type>&);
 
public:
    const linkedListType<Type>& operator=
          			      (const linkedListType<Type>&); 
		//Overload the assignment operator.
    void initializeList(); 
 		//Initializes the list to an empty state.
	    //Postcondition: first = NULL, last = NULL,
		//                count = 0
    bool isEmptyList();
 		//Function to determine whether the list is empty. 
		//Postcondition: Returns true if the list is empty;
		//               otherwise, returns false.
 
	int length();
		//Function to return the number of nodes in the 
		//list.
		//Postcondition: The value of count is returned.
    void destroyList();
 		//Function to delete all the nodes from the list.
  		//Postcondition: first = NULL, last = NULL, 
		//               count = 0
    Type front(); 
 		//Function to return the first element of the list.
 		//Precondition: The list must exist and must not be
		//empty.
  		//Postcondition: If the list is empty, then the 
 		//               program terminates; otherwise, 
	    //               the first element of the list is 
		//               returned.
    Type back(); 
       //Function to return the last element of the
       //list.
		//Precondition: The list must exist and must not
		//be empty.
		//Postcondition: If the list is empty, then the 
		//               program terminates; otherwise,
		//               the last element of the list is 
		//               returned.
 
   bool search(const Type& searchItem);
		//Function to determine whether searchItem is in 
		//the list.
		//Postcondition: Returns true if searchItem is found
		//               in the list; otherwise, it returns
		//               false.
 
    void insertFirst(const Type& newItem);
		//Function to insert newItem in the list.
		//Postcondition: first points to the new list 
		//                and newItem is inserted at the
		//                beginning of the list.
 
    void insertLast(const Type& newItem);
		//Function to return newItem at the end of the
		//list.
	    //Postcondition: first points to the new list, 
		//                newItem is inserted at the end
		//                of the list, and last points to
		//                the last node in the list.
 
    void deleteNode(const Type& deleteItem);
  		//Function to delete deleteItem from the list.
 		//Postcondition: If found, the node containing 
   		//               deleteItem is deleted from the 
		//                list, first points to the first
		//                node, and last points to the last 
		//                node of the updated list. 
 
	void deleteSmallest();
 
    linkedListType(); 
   		//default constructor
 		//Initializes the list to an empty state.
 		//Postcondition: first = NULL, last = NULL, 
		//               count = 0 
 
    linkedListType(const linkedListType<Type>& otherList); 
         //copy constructor
 
    ~linkedListType();   
    	//destructor
   		//Deletes all the nodes from the list.
    	//Postcondition: The list object is destroyed. 
 
protected:
    int count;		//variable to store the number of 
 					//elements in the list
    nodeType<Type> *first; //pointer to the first node of 
                           //the list
    nodeType<Type> *last;  //pointer to the last node of 
                           //the list 
private:
    void copyList(const linkedListType<Type>& otherList); 
		//Function to make a copy of otherList.
		//Postcondition: A copy of otherList is created 
		//               and assigned to this list.
};
 
template<class Type>
void linkedListType<Type>::deleteSmallest()
{
	Type smallest;
	//find the smallest value
	deleteNode(smallest);
}
 
template<class Type>
bool linkedListType<Type>::isEmptyList()
{
	return(first == NULL);
}
 
template<class Type>
linkedListType<Type>::linkedListType() // default constructor
{
	first = NULL;
	last = NULL;
	count = 0;
}
 
template<class Type>
void linkedListType<Type>::destroyList()
{
	nodeType<Type> *temp;   //pointer to deallocate the memory 
							//occupied by the node
	while(first != NULL)    //while there are nodes in the list
	{
	   temp = first;        //set temp to the current node
	   first = first->link; //advance first to the next node
	   delete temp;         //deallocate memory occupied by temp
	}
 
	last = NULL;	//initialize last to NULL; first has already
                   //been set to NULL by the while loop
 	count = 0;
}
 
	
template<class Type>
void linkedListType<Type>::initializeList()
{
	destroyList(); //if the list has any nodes, delete them
}
 
template<class Type>
int linkedListType<Type>::length()
{
 	return count;
}  // end length
 
template<class Type>
Type linkedListType<Type>::front()
{   
    assert(first != NULL);
   	return first->info; //return the info of the first node	
}//end front
 
 
template<class Type>
Type linkedListType<Type>::back()
{   
	 assert(last != NULL);
   	 return last->info; //return the info of the first node	
}//end back
 
template<class Type>
bool linkedListType<Type>::search(const Type& searchItem)
{
    nodeType<Type> *current; //pointer to traverse the list
    bool found;
 
    current = first; //set current to point to the 
                     //first node in the list
    found = false;   //set found to false
 
    while(current != NULL && !found)		//search the list
        if(current->info == searchItem)     //the item is found
           found = true;
        else
           current = current->link; //make current point 
                                    //to the next node
     
     return found;
}//end search
 
template<class Type>
void linkedListType<Type>::insertFirst(const Type& newItem)
{
	nodeType<Type> *newNode; //pointer to create the new node
 
	newNode = new nodeType<Type>; //create the new node
 
	assert(newNode != NULL);	//If unable to allocate memory, 
 								//terminate the program
 
	newNode->info = newItem; 	   //store the new item in the node
	newNode->link = first;        //insert newNode before first
	first = newNode;              //make first point to the 
                                 //actual first node
	count++; 			   //increment count
 
	if(last == NULL)   //if the list was empty, newNode is also 
                      //the last node in the list
		last = newNode;
}
 
template<class Type>
void linkedListType<Type>::insertLast(const Type& newItem)
{
	nodeType<Type> *newNode; //pointer to create the new node
 
	newNode = new nodeType<Type>; //create the new node
 
	assert(newNode != NULL);	//If unable to allocate memory, 
 							    //terminate the program
 
	newNode->info = newItem;      //store the new item in the node
	newNode->link = NULL;         //set the link field of newNode
         						//to NULL
 
	if(first == NULL)	//if the list is empty, newNode is 
     					//both the first and last node
	{
		first = newNode;
		last = newNode;
		count++;		//increment count
	}
	else			//the list is not empty, insert newNode after last
	{
		last->link = newNode; //insert newNode after last
		last = newNode;   //make last point to the actual last node
		count++;		//increment count
	}
}//end insertLast
 
template<class Type>
void linkedListType<Type>::deleteNode(const Type& deleteItem)
{
	nodeType<Type> *current; //pointer to traverse the list
	nodeType<Type> *trailCurrent; //pointer just before current
	bool found;
 
	if(first == NULL)    //Case 1; list is empty. 
		cerr<<"Can not delete from an empty list.\n";
	else
	{
		if(first->info == deleteItem) //Case 2 
		{
			current = first;
			first = first->link;
			count--;
			if(first == NULL)    //list has only one node
				last = NULL;
			delete current;
		}
		else  //search the list for the node with the given info
		{
			found = false;
			trailCurrent = first;   //set trailCurrent to point to
                                 //the first node
			current = first->link;  //set current to point to the 
    			   //second node
	
			while(current != NULL && !found)
			{
  				if(current->info != deleteItem) 
				{
					trailCurrent = current;
					current = current->link;
				}
				else
					found = true;
			} // end while
 
			if(found) //Case 3; if found, delete the node
			{
				trailCurrent->link = current->link;
				count--;
 
				if(last == current)      //node to be deleted was 
                                     //the last node
					last = trailCurrent;  //update the value of last
 
				delete current;  //delete the node from the list
			}
			else
				cout<<"Item to be deleted is not in the list."<<endl;
		} //end else
	} //end else
} //end deleteNode
 
 
	//Overloading the stream insertion operator
template<class Type>
ostream& operator<<(ostream& osObject, const linkedListType<Type>& list)
{
	nodeType<Type> *current; //pointer to traverse the list
 
	current = list.first;   //set current so that it points to 
					   //the first node
	while(current != NULL) //while more data to print
	{
	   osObject<<current->info<<" ";
	   current = current->link;
	}
 
	return osObject;
}
 
template<class Type>
linkedListType<Type>::~linkedListType() // destructor
{
	destroyList(); 
}//end destructor
 
 
template<class Type>
void linkedListType<Type>::copyList
            	      (const linkedListType<Type>& otherList) 
{
   nodeType<Type> *newNode; //pointer to create a node
   nodeType<Type> *current; //pointer to traverse the list
 
   if(first != NULL)	//if the list is nonempty, make it empty
	  destroyList();
 
   if(otherList.first == NULL) //otherList is empty
   {
		first = NULL;
		last = NULL;
 		count = 0;
   }
   else
   {
		current = otherList.first;  //current points to the 
									//list to be copied
		count = otherList.count;
 
			//copy the first node
		first = new nodeType<Type>;  //create the node
 
 		assert(first != NULL);
 
		first->info = current->info; //copy the info
		first->link = NULL;  	     //set the link field of 
									 //the node to NULL
		last = first;    		     //make last point to the 
            						 //first node
		current = current->link;     //make current point to  
           							 //the next node
 
			//copy the remaining list
		while(current != NULL)
		{
			newNode = new nodeType<Type>;  //create a node
 
			assert(newNode!= NULL);
 
			newNode->info = current->info;	//copy the info
			newNode->link = NULL;   	    //set the link of 
                                        //newNode to NULL
			last->link = newNode; 		//attach newNode after last
			last = newNode;   			//make last point to
										//the actual last node
			current = current->link;	//make current point to
       									//the next node
		}//end while
	}//end else
}//end copyList
 
 
	//copy constructor
template<class Type>
linkedListType<Type>::linkedListType
            	      (const linkedListType<Type>& otherList) 
{
	first = NULL;
 
	copyList(otherList);
	
}//end copy constructor
 
	//overload the assignment operator
template<class Type>
const linkedListType<Type>& linkedListType<Type>::operator=
   	 	 		(const linkedListType<Type>& otherList)
{ 
	if(this != &otherList) //avoid self-copy
		copyList(otherList);
 
	return *this; 
}
 
#endif

Basiaclly my question is... am I doing this correctly and can someone guide me into the right direction... also, i need to figure out how the user can actually put in the 10 numbers... what i have so far is

using namespace std;
 
#include "linkedList.h"
 
 
int main()
{
      linkedListType<int> list;
	  int num;
	  
	  cout<<"Pleas enter 10 numbers ==> \n"
        <<endl;										
	  cin>>num;										
	  
	  while(num >= 0)
	  {
           list.insert(num);
		  cin>>num;
	  }
 
	cout<<"The list before sorting:"<<endl;
	list.print();
	cout<<endl;
	list.selectionSort();
	cout<<"The list after sorting:"<<endl;
	list.print();
	cout<<endl;
 
	return 0;
}

This would mean so much for anyone who could help me!!!!

Recommended Answers

All 18 Replies

you need to create a loop and ask the the 10 numbers one at a time

for(int i = 0; i < 10; i++)
{
   cout << "Enter number #" << i+1 << "\n";
   cin >> num;
   list.push_back(num);
}

thanks Ancient Dragon, that helps but would you know if i wanted to find these sorted numbers would i have to make the sort function or is that already included in the header file, and if so, how am i able to attach those numbers so they are able to work along with the header file and when i try to compile my prgram it keeps giving me an error saying it cannot open linkedList.h, but what am i doing wrong or is this something that has to do with my settings?

Probably due to settings. What compiler and os are you using? Make sure the file "LinkedList.h" actually resides on your hard drive in the same directory as the *.cpp file you are trying to compile, and check the file's spelling. It doesn't have to be in the same directory, but makes life a lot easier if it is. As you gain more experience you will learn not to put header files in other directories.

i'm using windows... microsoft visual studio 2008

Well you can make a sort function, alternatively you can sort your inputs prior to pushing them into an array with a sort() function included in <algorithm.h>, but I doubt this is what your professor wants you to do. I suggest using a recursive function for sorting.

oh and although I'm not quite familiar with visual studio 2008, mabe you should have #include "LinkedListType.h" depending on how you saved your header file.

I resolved the header file issue... i played around with the settings and saved them both in the same file...
He said that he wants it in linked list not array but i'm still having problem with the sort function... i found an example online as follows:

template <typename Iterator>
void selection_sort(Iterator begin, Iterator end)
{
    Iterator min;
    while (begin != end)
    {
        min = std::min_element(begin, end);
        std::iter_swap(begin, min);
        ++begin;
    }
}

But i cant interpret that for what i'm working on... am i at least looking up the right information???

Can someone help me how to be able to add the numbers into some kind of memory spot where i can swap the values... i also found this online and i think this can help me but i dont know how to use it... help anyone??

Type temp = current->info;  // save value
    current->info = minnode->info;
    minnode->info = temp ;

also heres another question (i hope i dont sound stupid) But if I have to write up the numbers to be put into by the user, then also the coding for the selection sort, and also to swap the values to change the order... Isn't that the gist of the entire program?? what is the point of the header file?? How is helping me for the program as a whole??

im interpreting the question as you have

write a selection sort function which goes in the header.
write a cpp file that gets in ten numbers and calls functions to store the numbers into a linked list and sort it.
compile them together.

if im right then the header file is usefull as it contains functions for the linked list for use

all the c++ file should do is get the ten numbers most of the work is done by the header function calls

Oh okay cool, then my problem is actually connecting the c++ coding so it could work off of the header file... i'll work on that then, any tips or info would help out a lot i've never used a header file this whole semester we've only used the regular cpp its just very confusing for me thanks for everything!!

thanks for the link... i understand how to use visual studio... i just have trouble with the coding

Oh okay cool, then my problem is actually connecting the c++ coding so it could work off of the header file... i'll work on that then, any tips or info would help out a lot i've never used a header file this whole semester we've only used the regular cpp its just very confusing for me thanks for everything!!

its an faq to help you compile them together

I'm sorry let me rephrase more clearly i mean i can have the header execute in the program along with the cpp file, i just have trouble with connecting the coding between the header file and the cpp file for example to in the cpp file i want the user to pick 10 numbers then when the program runs (if ever) to understnad to run the code through the header file and the other way around as well

oh thats easy

you do this

object.functionname()

where object is what your manipulating and function name is one of the functions in the header

Its kind of like using a structure(with the inclusion of functions), if you make your class a pointer, use ->.

Thank you all so much you all have been so helpful... I will definitely keep posting if I have more questions... and thanks guys for being patient since I am a noob at this

ugh i still can't do it i'm very slow lol... thanks tho you guys have been helpful!!!!!

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