// vector.cpp
// definition for array-based, unsorted list ADT implementation
// based on listClass code in ListA.cpp from Carrano et al.

#include "vector.h"  

Vector::Vector() : Size(0)
{
}  // end default constructor

bool Vector::IsEmpty() const
{
   return bool(Size == 0);
}  // end IsEmpty

int Vector::GetLength() const
{
   return Size;
} // end GetLength

void Vector::InsertItem(int NewPosition,
                           listItemType NewItem,
                           bool &Success)
{
   Success = bool( (NewPosition >= 0) && 
                   (NewPosition <= Size) && 
                   (Size < 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 == Size)
      for (int Position = Size - 1; 
	   Position >= NewPosition;
	   --Position) {
	Items[Position + 1] = Items[Position];
      }


      // insert new item
      Items[NewPosition] = NewItem;
      ++Size;
   }  // end if
} // end InsertItem

void Vector::DeleteItem(int Position, bool &Success)
{
   Success = bool( (Position >= 0) && (Position < Size) );


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

void Vector::RetrieveItem(int Position,
                             listItemType &DataItem, 
                             bool &Success) const
{
   Success = bool( (Position >= 0) &&
                   (Position < Size) );


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

//  End of implementation file.