Thread: Doubly linked list add in order

I'm trying to create a doubly linked list that will add in order. I'm having trouble creating the AddInOrder method. Are there any web sources that any of you know of that could help me? or perhaps a part of my code that is not correct....or completely wrong .

Code:

void DList::AddAtHead(string& rsNewData) {
	DListNode* plnNew = new DListNode(rsNewData);
	plnNew-> plnNext = plnHead;
	if (plnHead != NULL) 
		plnHead-> plnPrev= plnNew;
	else plnTail = plnNew;
	plnHead= plnNew;
	++nNumItems ;
}

void DList::AddInOrder (string & rsNewData) {
	DListNode* plnNew = new DListNode(rsNewData);
	//If it's the first item
	if (nNumItems == 0) { 
		AddAtHead(rsNewData);
	}
	else
		//If it's smaller than the first - Add at start
		if (rsNewData <= plnHead->sWord) { 
			AddAtHead(rsNewData);
		}
		//If it's greater than the first - Loop through
		else {
			DListNode * plnCurrent = plnHead;
			plnCurrent = plnHead->plnNext;
			while (plnCurrent != plnHead) {
				if (plnCurrent->sWord < plnNew->sWord) 
					plnCurrent = plnCurrent->plnNext;
				else
					break;
			}
			plnNew->plnNext = plnCurrent;
			plnNew->plnPrev = plnCurrent->plnPrev;
			plnCurrent->plnPrev = plnNew;
			(plnNew->plnPrev)->plnNext = plnNew;
		}
}

Thanks for any help you can give,
Dan

If you keep indenting like that then you'll end up with very long lines. Usually else ifs are indented like so:

Code:

if(x) {
    /* ... */
}
else if(y) {
    /* ... */
}
else if(z) {
    /* ... */
}
else {

}

What exactly is wrong with your code? Does it crash? Does it insert items in the wrong places? Does it insert items at all?