Strange problem

[ILC]

Needed to create a pointer based linked list, overloaded the += operator in my class to add a value to the list. The operator inserts the value in order.

It works fine until the first value entered is either 0 or 1. Notice, this is only a problem for the FIRST value entered. These numbers work fine at any other insertion point. Whats up, what am i obviously missing? Oh yea, I get a core dump when I try that.

bool Set::operator +=(const unsigned int value)
{
	bool retValue = false;

	//if value is not in the Set
	if(!(*this%value))           //% checks to see whether or not the value is already in the list
	{
		if(head == NULL)		//add to empty list
		{
			head = new Node;
			assert(head != NULL);
			
			head->next = NULL;
			head->dataValue = value;
			retValue = true;
		}//end of if - adding to empty list
		else					//else - multiple nodes
		{
			Node *current = head;

			//value is less then the head
			if(value < current->dataValue)
			{
				cout<<"else if"<<endl;
				current = new Node;
				assert(current!=NULL);
				current->dataValue = value;
				current->next = head;
				head = current;
				
				retValue = true;
			}//end if - value should be head
			else
			{
				bool placed = false;

				Node *prev = current;
				current = current->next;

				if(placed == true)
					cout<<"true"<<endl;



				while(!placed)
				{
					//value should be in center
					if((value > prev->dataValue)
						&&(value < current->dataValue))
					{
						cout<<"while if"<<endl;
						current = new Node;
						assert(current!=NULL);
						current->next = prev->next;
						current->dataValue = value;
						prev->next = current;

						placed=true;
						retValue = true;
					}//end if - value in center
					//value is at the end
					else if(current->next == NULL)
					{
						cout<<"while else if"<<endl;
						prev = current;
						current = new Node;
						assert(current!=NULL);

						current->dataValue = value;
						current->next = NULL;
						prev->next = current;

						placed = true;
						retValue = true;
					}//end else if - add at end of Set
					//value should not be placed
					else
					{
						cout<<"while else"<<endl;
						//increment pointers
						prev=current;
						current = current->next;
					}//end of else - not placed;
				}//end of while - placing value
			}//end of else - multiple nodes, not head
		}//end of else - multiple Nodes
	}//end of if - value is in the set
	return retValue;
}//end of operator +=

Thanks.

ILC

P.S. I know it isn't the prettiest code, but I despise pointers. Any cout statements were for trying to debug.

[ILC]

Well, several hours and aspirin later, I have fixed it. No one ask what exactly caused it becuase I myself am not too sure.......

ILC

[vass0922]

so did you change anything in the code?
maybe we can see a difference...

[ILC]

Totally re-wrote the function.

bool Set::operator += (const unsigned int value)
{
	bool retValue = false;

	//if value is not in the list
	if(!(*this%value))
	{
		if(head == NULL)
		{
			head = addNewNode(value,NULL);
			retValue = true;
		}//end if - adding to empty list
		else if(value < head->dataValue)	//value should become the first node
		{
			head = addNewNode(value,head);
			retValue = true;
		}//end else if - value should be first node
		else	//value in middle or end
		{
			Node *current;
			Node *prev;

			current = head;
			bool run = true;
			//find location for pointer
			while(run)
			{
				if((current->next == NULL)||(current->dataValue > value))
					run = false;
				else
				{
					prev = current;
					current = current->next;
				}//end else
			}//end of while
			//add if needs to be last node
			if((current->next == NULL)&&(value > current->dataValue))
			{
				current->next = addNewNode(value,NULL);
				retValue = true;
			}//end if - adding last node
			else
			{
				prev->next = addNewNode(value,current);
				retValue=true;
			}//end of else
		}//end else - value not first
	}//end if - value in set

	return retValue;
}//end operator +=={

ILC