Delete the node in the odd position
1. Solution 1: 

void LinkedList::deleteOdd()
{
	int pos=1;
	Node * pre=head;
	Node * delnode=head;
	
	while(pre && delnode)
	{
		if(pos==1)
		{
			head=head->next;
			delete delnode;
			pre=head;
		}
		else if(pos%2==0)
		{
			delnode=pre->next;
       }
       else
       {
			pre->next=delnode->next;
			delete delnode;
			pre=pre->next;
		}
		pos++;
	}
}

2. Solution 2: 

void LinkedList::deleteOdd()
{
	Node *pre, *delnode;
	if (head)
	{
		delnode=head;
		head=head->next;
		delete delnode;
		pre=head;
	
		while(pre && pre->next)
		{
			delnode=pre->next;
			pre->next=delnode->next;
			delete delnode;
			pre=pre->next;
		}
	}
}

3. Solution 3: 

Node* LinkedList::deleteOdd(Node* h)
{
	If (!h) return 0; 
	Node * l = deleteEven(h->next);
	Delete h;
	Return l;
}

Node* LinkedList::deleteEven(Node* h)
{
	If (!h) return 0;
	h->next=deleteOdd(h->next);
	return h;
}