copy constructor-error in the insert before and after, can't find the problem

[humnbrd69]

I can't find why it won't output the correct info for the array. I've looked until I am ready to throw the computer out the door. I'm at my wits end trying to get this to work right. I finally got it to quit killing the compiler, but it's doing this. Does someone mine looking at it and instructing me as to what might be wrong. The problem is in the insertBefore or insertAfter function calls and I don't think that my copy constructor is right.

#include <iostream>
#include <cstdlib>
#include <fstream>
#include <iomanip>

using namespace std;

typedef int eletype;
int const CAPACITY = 20;

ofstream outfile;
ifstream infile;

class List
{
  public:
    List();
    List(List & x);
    bool empty() const;
    void front();
    void end();
    void prev();
    void next();
    int getPos() const;
    void setPos(int);
    void insertBefore(eletype);
    void insertAfter(eletype);
    eletype getElement();
    int size() const;
    void replace(eletype);
    void erase();
    void clear();
    void reverse();
    void swap(List & x);
    friend ostream& operator <<(ostream& output, List& x);
    friend List operator +(List &x, List &y);
    List &operator =(List &x);
  private:
    int curr_pos, t_size, check;
    eletype myArray[CAPACITY];

};

bool operator ==(List &x, List &y);

List::List()
{
    curr_pos = 1;
    t_size = 0;
    check = 0;
}

List::List(List & x)
{
    x.front();

    for(int i = 1; i <= x.size(); i++)
    {
        myArray[i] = x.getElement();
        x.next();
    }

    t_size = x.size();

    curr_pos = 1;
    check = 0;
}

bool List::empty() const
{
    if (t_size == 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

void List::front()
{
    curr_pos = 1;
    check = 0;
}

void List::end()
{
    curr_pos = t_size;
    check = 0;
}

void List::prev()
{
   curr_pos--;
}

void List::next()
{
    curr_pos++;
}

int List::getPos() const
{
    return curr_pos;
}

void List::setPos(int x)
{
    curr_pos = x;
}

void List::insertBefore(eletype x)
{
    if (curr_pos == (t_size) && check == 0)
    {
        curr_pos = CAPACITY;
    }

    if (curr_pos == 1)
    {
        t_size--;
    }

    myArray[(curr_pos - 1)] = x;

    curr_pos--;

    if (t_size != (CAPACITY - 1))
    {
        t_size++;
    }

    check = 1;
}

void List::insertAfter(eletype x)
{
    if (curr_pos == 1 && check == 0)
    {
        curr_pos = 0;
    }

    myArray[(curr_pos + 1)] = x;

    curr_pos++;

    if (t_size != (CAPACITY - 1))
    {
        t_size++;
    }

    check = 1;
}

eletype List::getElement()
{
    if (curr_pos < 1)
    {
        curr_pos = 1;
    }
    else if (curr_pos > t_size && t_size > 0)
    {
        curr_pos = t_size;
    }

    return myArray[curr_pos];
}

int List::size() const
{
    return t_size;
}

void List::replace(eletype x)
{
    myArray[curr_pos] = x;
}

void List::erase()
{
    myArray[curr_pos] = 0;
}

void List::clear()
{
    for (int i = 1; i < CAPACITY; i++)
    {
        myArray[i] = 0;
    }
}

void List::reverse()
{
    int hold, hold2;

    hold2 = t_size;

    for(int i = 1; i <= (t_size / 2); i++)
    {
        hold = myArray[i];
        myArray[i] = myArray[hold2];
        myArray[hold2] = hold;

        hold2--;
    }
}

void List::swap(List & x)
{
    int hold;

    x.front();

    for(int i = 1; i <= t_size; i++)
    {
        hold = myArray[i];
        myArray[i] = x.getElement();
        x.replace(hold);

        x.next();
    }
}

ostream& operator <<(ostream& output, List& x)
{
    x.front();

    if (x.size() == 0)
    {
        output << "\nThe list is empty.";
    }

    for (int i = 1; i <= x.size(); i++)
    {
        output << x.getElement() << " ";
        x.next();
    }

    output << endl;

    return output;
}

List operator +(List &x, List &y)
{
    List z;

    x.front();
    y.front();

    for (int i = 1; i <= y.size(); i++)
    {
        z.replace(x.getElement() + y.getElement());

        x.next();
        z.next();
        y.next();
    }

    return z;
}

List& List::operator =(List &x)
{
    x.front();

    for (int i = 1; i <= x.size(); i++)
    {
        myArray[i] = x.getElement();

        x.next();
    }

    t_size = x.size();
}

bool operator ==(List & x, List &y)
{
    int check = 0;

    x.front();
    y.front();

    if (x.size() == y.size())
    {
        for (int i = 1; i <= x.size(); i++)
        {
            if (x.getElement() != y.getElement())
            {
                check = 1;
            }

            x.next();
            y.next();
        }
    }
    else
    {
        check = 1;
    }

    if (check == 0)
    {
        return true;
    }
    else
    {
        return false;
    }
}

[wildblue]

If you can edit your post, highlight your code, then click on the <> button in the Format palette at the right side of the post, that'll format your code for the forum and make it a lot easier for others to read. :)

[humnbrd69]

I'm sorry but the program was too large so I had to split the List up and the main:

int main()
  {
    ofstream outfile ("General List Values.txt");

  	List a,b;  int endit;

	for (int i=1;i<=20;i++)
	   a.insertAfter(i);
	cout << "List a : " << endl;
    cout << "  "  << a << endl;
	cout << "Number of elements in a - " << a.size() << endl;

	for (int i=1;i<=20;i++)
	   b.insertBefore(i);
	cout << "List b : " << endl;
    cout << "  "  <<  b << endl;
	cout << "Number of elements in b - " << b.size() << endl;

	if ( a == b )
	    cout << "List a & b are equal" << endl;
	  else
	    cout << "List a & b are Not equal" << endl;

	a.front();
	b.front();
	cout << "First elmenet in list a & b: " << a.getElement() << ", "
				       << b.getElement() << endl;
	for ( int i = 0; i < a.size(); a.next(),i++);
	for ( int i = 0; i < b.size(); b.next(),i++);
	cout << "Last elmenet in list a & b: " << a.getElement() << ", "
				     << b.getElement() << endl;
	cout << endl << endl << " Start of new stuff" << endl;

	cout << "a = " << a << endl;
	cout << "b = " << b << endl;

	a.front();
	b.front();
	endit = a.size()/2;
	for ( int i = 1; i<endit; i++)
	{  a.next();
	   b.next();
	}

	cout << "New position in Obj 'a' position = " << a.size()/2 << endl;

	for ( int i=1; i<8; i++)
	{
	   a.erase();
	   b.replace(i);
	}

	cout << "Modified Object 'a' " << endl;
    cout << "List a: " << a << endl;

	List c(b);
	cout << "Copy Constructor c(b)" << endl;
    cout << "List b : " << b << endl;
    cout << "List c : " << c << endl;

	if ( c == b )
	    cout << "List c & b are equal" << endl;
	  else
	    cout << "List c & b are Not equal" << endl;


	List e;
	e = c;
	cout << "Object 'c' assigned to Object 'e':" << endl;
    cout << "List c : " << c << endl;
    cout << "List e : " << e << endl;

    List d;
	d=a;
	d.front();
	endit = d.size()/2;
	for (int i=1; i<=endit; i++)
	{
		d.next();
		d.erase();
	}
	cout << "Results after some erases: Object d  " << endl;
    cout << "List d : " << d << endl;

	d.front();
	endit = d.size();
	for ( int i = 1; i < endit; d.next(), i++)
	{
		d.insertBefore(d.getElement()*2);
		d.next();
	}
	cout << "Results after some Replaces on d " << endl;
    cout << "List d : " << d << endl;

	a.front();
	endit = a.size();
	for ( int i = 1; i < endit; a.next(), i++)
	{
		a.insertBefore(a.getPos()+a.getElement());
		a.next();
		a.erase();
	}
	cout << "Results after some weird stuff on list a" << endl;
    cout << "List a : " << a << endl;

    List alist(b);
    alist.clear();
    for (int i=1;i<=10;i++)
	   alist.insertAfter(i);
	alist.front();
	cout << "New List alist with positions above: " << endl;
    for (int i=1;i<=10;i++) {
		cout << setw(5) << alist.getPos();
		alist.next();
	}
	cout << endl;
	alist.front();
	for (int i=1;i<=10;i++) {
		cout << setw(5) << alist.getElement();
		alist.next();
	}
	cout << endl;

    alist.reverse();
    cout << "Reverse New List alist : " << endl;
    cout << "  "  << alist << endl;

    List newa;
    for (int i=1;i<=20;i++)
	   newa.insertAfter(i*3);
    cout << "List alist and newa before swap " << endl;
    cout << " " << alist << endl;
    cout << " " << newa << endl;
    alist.swap(newa);
    cout << "List alist and newa after swap " << endl;
    cout << " " << alist << endl;
    cout << " " << newa << endl;


	cout << endl << "check out boundary conditions" << endl;
	List sq;
	cout << "number of elements in empty sq list = " << sq.size() << endl;
	sq.front();
	sq.erase();
	cout << "empty sq values " << sq << endl;
	sq.insertBefore(999);
	cout << "sq values " << sq << endl;
	sq.next(); sq.next();
	cout << "sq.getElement() = " << sq.getElement() << endl;
	cout << "sq values " << sq << endl;
	system("pause");   //This statement not needed in code blocks, just VS.
	return 0;
  }

[ne555]

http://www.cplusplus.com/forum/general/112111/

foo.cpp: In member function ‘List& List::operator=(List&)’:
foo.cpp:276:1: warning: no return statement in function returning non-void [-Wreturn-type]

> I can't find why it won't output the correct info for the array.
¿what should output?

void List::insertAfter(eletype x)
{
    if (curr_pos == 1 && check == 0)
    {
        curr_pos = 0;
    }

    myArray[(curr_pos + 1)] = x; //out of bound access

    curr_pos++;

    if (t_size != (CAPACITY - 1))
    {
        t_size++;
    }

    check = 1;
}