Question

Java

implement the method in IteratorExercise.java using only list iterator methods:

bubbleSort: sort the provided list using bubble sort

Do not modify the test code in each function. You can look at that code for some ideas for implementing the methods.

import java.lang.Comparable;
import java.util.*;

public class IteratorExercise {
  
   public static <E extends Comparable<? super E>> void bubbleSort(List<E> c) throws Exception {
       // first line to start you off
       ListIterator<E> iit = c.listIterator(), jit;

       /**** Test code: do not modify *****/
       List cc = new LinkedList(c);
       Collections.sort(c);
       ListIterator it1 = c.listIterator(), it2 = cc.listIterator();
    while (it1.hasNext()) {
      if (!it1.next().equals(it2.next()))
               throw new Exception("List not sorted");
    }
       /***********************************/
   }

public static <E> void reverseList(List<E> c) throws Exception {
       /**** Test code: do not modify *****/
       LinkedList cc = new LinkedList(c);
       /***********************************/

       // Reverse the list using iterators. Do not use List methods

   /**** Test code: do not modify *****/
       Iterator it1 = c.listIterator(), it2 = cc.descendingIterator();
       while (it1.hasNext()) {
      if (!it1.next().equals(it2.next()))
               throw new Exception("List not reversed");
    }
       /***********************************/
}

   public static <E> void removeEveryOtherElement(List<E> c) throws Exception {
       /**** Test code: do not modify *****/
       LinkedList cc = new LinkedList(c);
       /***********************************/

       // Remove every other element (starting with the second element:
       // all odd indices)

   /**** Test code: do not modify *****/
       printList(cc);
       printList(c);
       ListIterator it1 = c.listIterator(), it2 = cc.listIterator();
       while (it1.hasNext()) {
      if (!it1.next().equals(it2.next()))
               throw new Exception("Even indices not equal");
           if (!it1.hasNext()) break;
           if (it1.next().equals(it2.next()))
               throw new Exception("Odd index not removed");
           it1.previous();
    }
       /***********************************/
   }

   public static void printList(List c) {
       StringBuilder str = new StringBuilder();
       String sep = " ";
       for (Object i : c) {
           str.append(i);
           str.append(sep);
       }
       System.out.println(str.toString());
   }

   public static void fillList(List<Integer> c) {
       Random r = new Random();
       for (int i = 0; i < 23; i++) c.add(i);
       Collections.shuffle(c);
   }

   public static void main(String[] args) {
       try {
       List<Integer> lst = new ArrayList<Integer>();
       fillList(lst);

       bubbleSort(lst);

       removeEveryOtherElement(lst);

       reverseList(lst);
       } catch (Exception e) { System.err.println(e.getMessage()); }
   }

Answer 1

ANSWER:

OUTPUT:

CODE:

public static void removeEveryOtherElement(List c) throws Exception {
/*** Test code: do not modify ****/
LinkedList cc = new LinkedList(c);
/***********************************/

// Remove every other element (starting with the second element:
// all odd indices)
ListIterator it = c.listIterator();
while(it.hasNext()) {
it.next(); // even index
if(it.hasNext()) {
it.next(); //odd index
it.remove();
}
}