lista.h

Data Abstraction & Problem Solving with C++源码

// *********************************************************
// Header file ListA.h for the ADT list
// Array-based implementation
// *********************************************************
const int MAX_LIST = maximum-size-of-list;
typedef desired-type-of-list-item ListItemType;

class List
{
public:
   List();  // default constructor
            // destructor is supplied by compiler

// list operations:
   bool isEmpty() const;
   // Determines whether a list is empty.
   // Precondition: None.
   // Postcondition: Returns true if the list is empty;
   // otherwise returns false.

   int getLength() const;
   // Determines the length of a list.
   // Precondition: None.
   // Postcondition: Returns the number of items
   // that are currently in the list.

   void insert(int index, ListItemType newItem,
               bool& success);
   // Inserts an item into the list at position index.
   // Precondition: index indicates the position at which
   // the item should be inserted in the list.
   // Postcondition: If insertion is successful, newItem is
   // at position index in the list, and other items are
   // renumbered accordingly, and success is true;
   // otherwise success is false.
   // Note: Insertion will not be successful if
   // index < 1 or index > getLength()+1.

   void remove(int index, bool& success);
   // Deletes an item from the list at a given position.
   // Precondition: index indicates where the deletion
   // should occur.
   // Postcondition: If 1 <= index <= getLength(),
   // the item at position index in the list is
   // deleted, other items are renumbered accordingly,
   // and success is true; otherwise success is false.

   void retrieve(int index, ListItemType& dataItem,
                 bool& success) const;
   // Retrieves a list item by position.
   // Precondition: index is the number of the item to
   // be retrieved.
   // Postcondition: If 1 <= index <= getLength(),
   // dataItem is the value of the desired item and
   // success is true; otherwise success is false.

private:
   ListItemType items[MAX_LIST];  // array of list items
   int          size;             // number of items in list

   int translate(int index) const;
   // Converts the position of an item in a list to the
   // correct index within its array representation.
};  // end List class
// End of header file.