c++ skip list implementation?

[bob135]

I'm having trouble implementing a skip list. It's supposed to store rectangles and order them by a key which is a character array, using strcmp to order them correctly.

Obviously its screwed up somewhere but I'm not sure what's wrong. I step through and it breaks on the line right after the first if statement in the insert function, giving me an access violation.

This is what I have so far:

int randomH(){
	int h=1;//h must be at least 1
	while((rand() % 2) == 1){//with a coin flip, increase h
		h++;
	}
	return h;
}

node::node(char *myKey, int myX, int myY, int myH, int myW){
	key = myKey;
	x=myX;
	y=myY;
	h=myH;
	w=myW;

	height = randomH();
	forward = new node*[height];
}

skiplist::skiplist(){
	NIL = new node("THE_END",-1,-1,-1,-1);
	head = new node("THE_HEAD",-1,-1,-1,-1);
	listheight = head->height;
	for(int i=0;i<listheight;i++){
		head->forward[i] = NIL;
	}
}

void skiplist::insert(char *myKey, int myX, int myY, int myH, int myW){
	node *inserted = new node(myKey, myX, myY, myH, myW);//make the node to insert

	int i = inserted->height - 1;//track the height (start at the top)
	node *pos = head;//track the position (start at the head)

	while(i > -1){//until we try to drop "below" the tree
		if(pos->forward[i] == NIL || strcmp( pos->forward[i]->key, myKey) > 0){//if the node to the right is NIL or is bigger, add a pointer and go down a level
			inserted->forward[i] = pos->forward[i]; //the node being inserted points to the node pos pointed to
			pos->forward[i] = inserted; //the position prior to that node now points to it
			i--;
		}
		else if( strcmp( pos->forward[i]->key, myKey) < 0){//if the node to the right is smaller, go forward one
			pos = pos->forward[i];
		}
		else{//otherwise they're equal
			inserted->forward[i] = pos->forward[i]; //the node being inserted points to the node pos pointed to
			pos->forward[i] = inserted; //the position prior to that node now points to it			
		}
	}

	
	if(inserted->height > listheight){//and if the new node has a height in excess of the existing structure....
		node **tempForward = new node*[inserted->height]; //make a new array
		tempForward = head->forward; //store the existing head's forward array in it

		delete head->forward;//delete the old one
		head->forward = new node*[inserted->height];//remake it
		head->forward = tempForward;//copy old data to the new one

		for(int k = inserted->height - 1; k > listheight - 1; k--){
			head->forward[k] = inserted;
		}
	}

}