De Dup. java in a programe

DeDup.java

public class DeDup

 { 

    public static void main(String[] args)

   {

        SET distinct = new SET();

        while (!StdIn.isEmpty())

   {

            String key = StdIn.readString();

            if (!distinct.contains(key))

   {

                distinct.add(key);

                StdOut.println(key);

            }

        }

    }

}