Linked list node deletion troubles

[groovinbassplaya]

I was having problems with this program before but pushed through most of them. However, I keep encountering a run-time error when my "Kill" function is called.

void LinkedList::Kill(int order)
{
	nodePtr cursor = First, temp;
	while(Count() > 1)
	{
		for(int i = 1; i < order; i++)
		{
			temp = cursor;
			temp = temp->next;
			cursor->next = temp->next;
			delete temp;
		}
		 cursor = cursor->next;
	}
	cout << "Person #" << cursor->info << " survived!" << endl;
}

It's supposed to take the order that the nodes should be deleted as a parameter. (For example if the order is 2, every second node should be deleted until only one is left.) I have the list linked circularly so the last node's next node is the beginning node. Is there something I'm missing here?

[groovinbassplaya]

It appears that my problem is with my constructor, not the Kill function.

LinkedList::LinkedList(int size)
{
	nodePtr cursor, preCursor;
	for(int i = 0; i < size; i++)
	{
		cursor = new Node;
		cursor->info = (i + 1);
		preCursor = cursor;
		cursor = cursor->next;
	}
	preCursor->next = First;
}

I'm getting a bit frustrated with this as it's due by midnight.

[zwA4jE8b]

nodePtr cursor = First, temp;

this line seems a little wierd, are you trying to declare first and temp as nodeptr's?

you cannot declare cursor and set it equal to two variables

[zwA4jE8b]

or are you trying to declare 3 nodeptr's nodePtr cursor, First, temp;

in your constructor you cannot have cursor = cursor->next; because you have not declared what next points. You tell it what the info should be but not next. if cursor is a new node then how can cursor = the node it points to if it just came into existence

[groovinbassplaya]

Maybe I should include the whole program to weed out any discrepancies.
This is the header file.

#include <iostream>
using namespace std;

class LinkedList
{ private:
  class Node
  {
   public:
    int info;
    Node *next;
  };
  typedef Node *nodePtr;
 
 public:		
	LinkedList(int size);
	~LinkedList();
	void Kill(int order);
	int Count();
	bool Empty();
  private:
      nodePtr First;
};
LinkedList::LinkedList(int size)
{
	nodePtr cursor, preCursor;
	for(int i = 0; i < size; i++)
	{
		cursor = new Node;
		cursor->info = (i + 1);
		preCursor = cursor;
		cursor = cursor->next;
	}
	preCursor->next = First;
}
LinkedList::~LinkedList()
{
	nodePtr cursor = First;
	while(cursor !=0)
	{
		First = First->next;
		delete cursor;
		cursor = First;
	}
}
void LinkedList::Kill(int order)
{
	nodePtr cursor = First, temp;
	while(cursor->next != cursor)
	{
		for(int i = 1; i < order; i++)
		{
			temp = cursor;
			temp = temp->next;
			cursor->next = temp->next;
			delete temp;
		}
		 cursor = cursor->next;
	}
	cout << "Person #" << cursor->info << " survived!" << endl;
}
int LinkedList::Count()
{
	nodePtr cursor = First;
	int sum;
	if(!Empty())
	{
		for(sum = 1; cursor != 0; sum++)
			cursor = cursor->next;
	}
	else
		sum = 0;
	return sum;
}
bool LinkedList::Empty()
{
	return (First == 0);
}

And this is the driver.

#include <iostream>
#include "LinkedList.h"
using namespace std;

int main()
{
	int captives, killOrder;
	cout << "Enter the number of captives: ";
	cin >> captives;
	LinkedList circle(captives);
	cout << endl << "Now enter the order that they will be killed: ";
	cin >> killOrder;
	circle.Kill(killOrder);
	return 0;
}

[naraku9333]

You should step through the whole thing with a debugger, I dont think your ctor works.

[groovinbassplaya]

So I'm thinking it would be beneficial to remove preCursor completely from the ctor, as well as the cursor = cursor->next line, then write a separate function to put the nodes into order. I suppose I'll give that a try.

[naraku9333]

The problem in your ctor is you need cursor->next = new Node;
before cusor = cursor->next;