// List.cpp - implementation file for linked list List ADT

#include <iostream>
using namespace std;

#include "List.h"

//-- Definition of the class constructor
List::List() : first(0), mySize(0)
{ }

//-- Definition of the copy constructor
List::List(const List & origList)
{
   mySize = origList.mySize;
   
   first = 0;
   if (mySize == 0)
      return;

   List::NodePointer origPtr, lastPtr;
   
   first = new Node(origList.first->data); // copy first node
   lastPtr = first;
   origPtr = origList.first->next;

   while (origPtr != 0)
   {
      lastPtr->next = new Node(origPtr->data);
      origPtr = origPtr->next;
      lastPtr = lastPtr->next;
   }
}

//-- Definition of the destructor
inline List::~List()
{
   List::NodePointer prev = first, ptr;
   
   while (prev != 0)
   {
      ptr = prev->next;
      delete prev;
      prev = ptr;
   }
}

//-- Definition of the assignment operator
const List & List::operator=(const List & rightSide)
{
   mySize = rightSide.mySize;

   first = 0;
   if (mySize == 0)
      return *this;

   if (this != &rightSide)
   {
      this->~List();
      List::NodePointer origPtr, lastPtr;
      first = new Node(rightSide.first->data); // copy first node
      lastPtr = first;
      origPtr = rightSide.first->next;
      while (origPtr != 0)
      {
         lastPtr->next = new Node(origPtr->data);
         origPtr = origPtr->next;
         lastPtr = lastPtr->next;
      }
   }
   return *this;
}

// Definition of empty()
bool List::empty()
{
   return mySize == 0;
}

//-- Definition of insert()
void List::insert(ElementType dataVal, int index)
{
   if (index < 0 || index > mySize)
   {
      cerr << "Illegal location to insert -- " << index << endl;
      return;
   }
   mySize++;
   List::NodePointer newPtr = new Node(dataVal),
   predPtr = first;
   if (index == 0)
   {
      newPtr->next = first;
      first = newPtr;
   }
   else
   {
      for(int i = 1; i < index; i++)
         predPtr = predPtr->next;
      newPtr->next = predPtr->next;
      predPtr->next = newPtr;
   }
}

//-- Definition of erase()
void List::erase(int index)
{
   if (index < 0 || index >= mySize)
   {
      cerr << "Illegal location to delete -- " << index << endl;
      return;
   }
   mySize--;
   List::NodePointer ptr,
   predPtr = first;
   if (index == 0)
   {
      ptr = first;
      first = ptr->next;
      delete ptr;
   }
   else
   {
      for(int i = 1; i < index; i++)
         predPtr = predPtr->next;
      ptr = predPtr->next;
      predPtr->next = ptr->next;
      delete ptr;
   }
}