// Chap 3, pp 133 - 135
// Change the name of this file to ListA.cpp

// *********************************************************
// Implementation file ListA.cpp for the ADT list.
// Array-based implementation.
// *********************************************************
#include "ListA.h"  // header file

listClass::listClass() : Size(0)
{
}  // end constructor

listClass::listClass(const listClass& L): Size(L.Size)
{
   for (int Position = 1; Position <= L.Size; ++Position)
      Items[Index(Position)] = L.Items[Index(Position)];
}  // end copy constructor

listClass::~listClass()
{
}  // end destructor

boolean listClass::ListIsEmpty()
{
   return boolean(Size == 0);
}  // end ListIsEmpty

int listClass::ListLength()
{
   return Size;
} // end ListLength

void listClass::ListInsert(int NewPosition,
			   listItemType NewItem,
			   boolean& Success)
{
   int LastPosition = ListLength();

   Success = boolean( (NewPosition >= 1) &&
		      (NewPosition <= LastPosition+1) &&
		      (LastPosition < MAX_LIST) );

   if (Success)
   {  // make room for new item by shifting all items at
      // positions >= NewPosition toward the end of the
      // list (no shift if NewPosition == LastPosition+1)
      for (int Position = LastPosition;
	       Position >= NewPosition; --Position)
	 Items[Index(Position+1)] = Items[Index(Position)];

      // insert new item
      Items[Index(NewPosition)] = NewItem;
      ++Size;
   }  // end if
} // end ListInsert

void listClass::ListDelete(int Position,
			   boolean& Success)
{
   int LastPosition = ListLength();

   Success = boolean ( (Position >= 1) &&
		       (Position <= LastPosition) );

   if (Success)
   {  // delete item by shifting all items at positions >
      // Position toward the beginning of the list
      // (no shift if Position == LastPosition)
      for (int FromPosition = Position+1;
	       FromPosition <= LastPosition; ++FromPosition)
	 Items[Index(FromPosition-1)] =
				 Items[Index(FromPosition)];
      --Size;
   }  // end if
}  // end ListDelete

void listClass::ListRetrieve(int Position,
			     listItemType& DataItem,
			     boolean& Success)
{
   int LastPosition = ListLength();

   Success = boolean ( (Position >= 1) &&
		       (Position <= LastPosition) );

   if (Success)
      DataItem = Items[Index(Position)];
 } // end ListRetrieve

int listClass::Index(int Position)
{
   return Position-1;
} // end Index
//  End of implementation file.