#include "LinkedList.h"

/* LinkedNode functions 
 * */

LinkedNode::LinkedNode(LinkedNode *nxt, int e) {
  next = nxt;
  element = e;
}

LinkedNode::LinkedNode(int e) : LinkedNode(NULL,e) { } 
int LinkedNode::getElement() { return element; }
LinkedNode* LinkedNode::getNext() { return next; } 
void LinkedNode::setElement(int  e) { element = e; }
void LinkedNode::setNext(LinkedNode *nxt) { next = nxt; }

/* LinkedList functions 
 * */

LinkedList::LinkedList() {
  listSize = 0;
  head = NULL;
}

int LinkedList::size() { return listSize; }

void LinkedList::insertFirst(int o) {
  LinkedNode *node = new (nothrow) LinkedNode(head, o);
  head = node;
  listSize++;
}

void LinkedList::insertAfter(LinkedNode *prev, int o) {
  LinkedNode *node = new (nothrow) LinkedNode(prev->getNext(), o);
  prev->setNext(node);
  listSize++;  
}

int LinkedList::deleteFirst() {
  if(size()==0)
    return -1;
  LinkedNode *node = head;
  head = head->getNext();
  int o = node->getElement();
  delete node;
  listSize--;
  return o;
}

int LinkedList::deleteAfter(LinkedNode *prev) {
  LinkedNode *node = prev->getNext();
  prev->setNext(node->getNext());
  int o = node->getElement();
  delete node;
  listSize--;
  return o;
}

int LinkedList::valueAt(int pos) {
  if(pos >= size() )
    return -1;
  LinkedNode *curr = head;
  for(int i=0; i<pos; i++, curr=curr->getNext() )
    ;
  return curr->getElement();
    
}