COP 3337
Section U08
Fall 2015



                           The Lists Class
                           ==============


I. The Lists.java class


import java.util.Collections;
import java.util.LinkedList;
import java.util.ListIterator;

public class Lists 
{
    // sort list in increasing order
    public static <T extends Comparable<? super T>>
            void sort(LinkedList<T> list)
    {
        
        Collections.sort(list);
    }        

    
    // reverse
    // sort list in increasing order
    public static <T extends Comparable<? super T>>
            void reverse(LinkedList<T> list)
    {
        
        Collections.reverse(list);
    }        
    
    // list is not null
    // list is sorted in increasing order
    // if x is not in the list, insert it in its proper place
    // and return true
    // if x is in the list, return false
    public static <T extends Comparable<? super T>>
            boolean insert(T x, LinkedList<T> list)
    {
         // form an iterator
        ListIterator<T> ite = list.listIterator();
        // advance to the end of the list or to the first item >= x
        while (ite.hasNext())
        {
            T current = ite.next();
            if (current.equals(x))
                return false;
            if (current.compareTo(x) > 0)
            {
                // go back
                ite.previous(); 
                break;
            }     
        }
        // insert here
        ite.add(x);
        return true;
    }
    
    public static <T> void print( LinkedList<T> list)
    {
        if (list == null || list.size() == 0)
            System.out.println("The list is empty.");
        else
        {
            for (T curr : list)
                System.out.println(curr);
        }    
    }        
}


II. The Driver


import java.util.LinkedList;

public class ListMethods {

    // test lists
    public static void main(String[] args) 
    {
        System.out.println("Testing Lists");
        System.out.println("=============\n\n");
        System.out.println("We add the names Papa Bill, Mark,"
                + "Grandpa, Ana, Mark.");
        
        LinkedList<String> names = new LinkedList();
        Lists.insert("Papa Bill", names);
        Lists.insert("Mark", names);
        Lists.insert("Grandpa", names);
        Lists.insert("Ana", names);
        Lists.insert("Mark", names);
        
        System.out.println("\nWe print the list of names.");
        Lists.print(names);
        
    }
}


III. The Output

Testing Lists
=============


We add the names Papa Bill, Mark,Grandpa, Ana, Mark.

We print the list of names.
Ana
Grandpa
Mark
Papa Bill
BUILD SUCCESSFUL (total time: 0 seconds)