2.1.1 A Program with List ADT

A program given below is independent of which data structure is used to implement the list ADT. This is an example of the notion of encapsulation in object oriented programming.

Purpose:

To eliminate all duplicates from a list

Given:

1.

Elements of list L are of element type

2.

function same (x, y), where x and y are of element type, returns true if x and y are same, false otherwise

3.

p and q are of type position

p : current position in L

q : moves ahead to find equal elements

Pseudocode in C:

{

        p = first (L) ;

            while (p! = end(L)) {

                q = next(p, L) ;

                while (q! = end(L)) {

                    if (same (retrieve (p,L), retrieve (q, L))))

                        delete (q,L);

                    else

                        q = next (q, L) ;

                    }

                   p = next (p, L) ;

                   }

}