Question

Hi - So again I'm having some trouble getting started. Here is my assignment:

For this assignment we’ll be

creating a new class called, Utilities

.

The Utilities class will contain

two methods;

removeDuplicates and linearSearch RemoveDuplicates

public<T> voidremoveDuplicates(finalList<T> items)

Write a generic method that removes duplicate items from the supplied List

.

For example:

List<String> strings

=

new

ArrayList<>();

strings.add("one");

strings.add("two");

strings.add("one");

Utilities utilities =

new

Utilities();

utilities.removeDuplicates(strings);

The result is the list of strings contains two records;

“one” and “two”.

List<String> strings = newArrayList<>();

strings.add("one");

strings.add("one");

strings.add("one");

Utilities utilities = new Utilities();

utilities.removeDuplicates(strings);

The result is the list of strings contains one record; “one”.

LinearSearch Implement a generic method to do a linear search. Your linear search method should accept a list containing a generic type, and a key record to search for in the generic list. Your search should return the record associated with the supplied key or null if the key does not exist in the supplied list.

public <E> E linearSearch(List<E> list, E key)

Answer 1

// Utilities.java

import java.util.ArrayList;

import java.util.List;

public class Utilities {

       // generic method to remove duplicates from a list

       public<T> void removeDuplicates(List<T> items)

       {

             for(int i=0;i<items.size();i++)

             {

                    for(int j=i+1;j<items.size();j++)

                           if(items.get(i).equals(items.get(j)))

                           {

                                 items.remove(j);

                                 j--;

                           }

             }

       }

      

       // generic method to find and return the record associated with the key or null, if record not present

       public <E> E linearSearch(List<E> list, E key)

       {

             for(int i=0;i<list.size();i++)

                    if(list.get(i).equals(key))

                           return list.get(i);

             return null;

       }

      

       public static void main(String[] args) {

      

             List<String> strings=new ArrayList<>();

             strings.add("one");

             strings.add("two");

             strings.add("one");

            

             Utilities utilities =new Utilities();

             utilities.removeDuplicates(strings); //test the removeDuplicates

             System.out.println(" Strings list after removing duplicates : ");

             for(int i=0;i<strings.size();i++)

                    System.out.println(strings.get(i));

             System.out.print("\n Find \"one\" in Strings list : ");

             System.out.println(utilities.linearSearch(strings, "one"));

             System.out.print("\n Find \"three\" in Strings list : ");

             System.out.println(utilities.linearSearch(strings, "three"));

       }

}

//end of Utilities.java

Output: