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Segmentation Faults, need help tracking a few down

mistabob (35)
Hello! I've written a simple Queue list with a linked list format. Unfortunately, I am getting several seg faults that I can't seem to track down.

Here is my Queue.h, where I believe they reside:

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#ifndef QUEUE_H
#define QUEUE_H

#include "Node.h"
#include "QueueException.h"

using namespace std;

template <typename T>
class Queue 
{
public:
Node<T>* head;
Node<T>* current;
int cnt;

Queue();
Queue(T data);
Queue(const Queue &rhs);
const Queue & operator=(const Queue &rhs); 
~Queue();
void enqueue(T data);
T dequeue() throw (QueueException);
T front() throw (QueueException);
bool isEmpty();
};

template <typename T>
Queue<T>::Queue()
{
	head = NULL;
	current = NULL;
	cnt = 0;
}

template <typename T>
Queue<T>::Queue(T data)
{
	head = new Node<T>(data,NULL);
	current = head;
	cnt = 1;
}

template <typename T>

Queue<T>::~Queue()
{
	Node<T>* curr = head;
	while(current != NULL)
	{
		Node<T>* next = curr->next;
		delete curr;
		curr = next;
	}
	head = NULL;
}

template <typename T>
Queue<T>::Queue(const Queue<T> &rhs)
{
	cnt = rhs.cnt;
    head = NULL;
    if (rhs.head != NULL)
    {
        head = new Node<T>(rhs.head->getData());
        Node<T>* curr = head;
        Node<T>* otherCurr = rhs.head->getNext();
        while(otherCurr != NULL)
        {
            curr->setNext(new Node<T>(otherCurr->getData()));
            curr = curr->getNext();
            otherCurr = otherCurr->getNext();
        }
    }

}

template <typename T>
bool Queue<T>::isEmpty()
{
	if(cnt == 0)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}

template <typename T>
T Queue<T>::front() throw(QueueException)
{
	if(cnt == 0)
	{
		throw QueueException();
	}
	return head->data;
}

template <typename T>
T Queue<T>::dequeue() throw (QueueException)
{
	T toRemove;
	  toRemove = head->getData();
        head = head->getNext();
        cnt--;
        return toRemove;
}

template <typename T>
void Queue<T>::enqueue(T newdata)
{
    if(head != NULL)
    {
        current = head;
        while(current->getNext() != NULL)
        {
            current = current->getNext();
        }
        Node<T>* newinsert = new Node<T>(newdata, NULL);
        current->setNext(newinsert);
    }
    else
    {
        Node<T>* newinsert = new Node<T>(newdata, NULL);
        head = newinsert;
    }
    cnt++;
}


template <typename T>
const Queue<T>& Queue<T>::operator=(const Queue<T> &rhs)
{
		cnt = rhs.cnt;
    head = NULL;
    if (rhs.head != NULL)
    {
        head = new Node<T>(rhs.head->getData());
        Node<T>* curr = head;
        Node<T>* otherCurr = rhs.head->getNext();
        while(otherCurr != NULL)
        {
            curr->setNext(new Node<T>(otherCurr->getData()));
            curr = curr->getNext();
            otherCurr = otherCurr->getNext();
        }
    }

}

#endif



I know I need to learn to track these down myself, but I'm at my wit's end with these. Unfortunately, this block of code is a bit of an amalgamation of snippets from several previous programs (generic linked list template and its accompanying Node class).

Thank you for any help you can provide!
Last edited on
pogrady (677)
Which function do the segmentation faults occur.
cire (8284)
Node definition?

Memory leak in dequeue, btw.

Supplying a minimal 'main' in which the segmentation fault is reproducible would be good.
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