Question 1. Write a method for the AList class that returns the first position o

Question

Question 1.

Write a method for the AList class that returns the first position of a given object in the list with the method header below.

public int getPosition(T anObject)

Question 2.

Write a method for the AList class that moves the last item in the list to the beginning of the list.

public void moveToBeginning()

Question 3. Write an equals method for the AList class to override the method inherited from Object. Two lists are logically the same if they contain the same elements in the same order.

Question 4.

Have the AList class implement the Comparable interface.

Write the compareTo method to order lists this way:

first by size: a list that has fewer elements is smaller

second by the first element: if the lists have the same size, then compare the order of the first element on the list

Note, to test your AList class, use these class and method headers:

public class AList<T extends Comparable> implements ListInterface<T>, Comparable<AList<T>>

public int compareTo(AList<T> otherList)

You also need to change the lines in the constructor and toArray methods from using Object to using Comparable:

T[] tempList = (T[]) new Comparable[initialCapacity + 1];

T[] result = (T[]) new Comparable[numberOfEntries]; // Unchecked cast

Examples:

List A: 1, 5, 6, 8, 10

List B: 2, 4, 3, 9, 7

In this example, List A is smaller because the lists are the same size and the first element of Lisa A is smaller than the first element of List B.

List A: 1, 2, 3, 10, 9

List B: 2, 4, 3, 7

In this example, List B is smaller because it has fewer elementss.

List A: 1, 4, 6, 2, 3

List B: 1, 5, 7, 2, 9

In this example, the compareTo method would return 0 because the lists are the same size and their first element is the same. (Note that it's true the lists aren't equal!)

Driver program:

import java.util.Arrays;

public class Homework04Driver {

public static void main(String[] args) {

// setting up an ArrayBag to test

System.out.println("TESTING BAG");

ArrayBag<Integer> numbersBag = new ArrayBag<Integer>();

numbersBag.add(1);

numbersBag.add(2);

numbersBag.add(1);

numbersBag.add(4);

numbersBag.add(3);

System.out.println("The bag contains[1, 2, 1, 4, 3]

"

+

// Q7: getPosition

// Note: this driver assumes you return -1 if an element

is not in the list;

// it would also be valid to throw an exception

System.out.println(" ***Q7***");

System.out.println("Position is 1: " +

produceList.getPosition("banana"));

System.out.println("Position is 3: " +

produceList.getPosition("grape"));

System.out.println("Position is -1: " +

produceList.getPosition("mango"));

//Q8: moveToBeginning

System.out.println(" ***Q8***");

System.out.println("List contains [banana, date, grape,

eggplant, jicama, grape] "

+

Arrays.toString(produceList.toArray()));

produceList.moveToBeginning();

System.out.println("List contains [grape, banana, date,

grape, eggplant, jicama] "

+

Arrays.toString(produceList.toArray()));

produceList.clear();

produceList.moveToBeginning();

System.out.println("List contains [] "

+

Arrays.toString(produceList.toArray()));

// Q9: equals

System.out.println(" ***Q9***");

produceList.add("banana");

produceList.add("potato");

produceList.add("jicama");

produceList.add("grape");

AList<String> foodList = new AList<String>();

foodList.add("banana");

foodList.add("potato");

foodList.add("jicama");

System.out.println("Result is false: " +

produceList.equals(foodList));

foodList.add("grape");

System.out.println("Result is true: " +

produceList.equals(foodList));

foodList.add("squash");

System.out.println("Result is false: " +

produceList.equals(foodList));

foodList.replace(1, "jicama");

foodList.replace(3, "banana");

System.out.println("Result is false: " +

produceList.equals(foodList));

System.out.println("The list contains[banana, potato,

jicama, grape] "

+

Arrays.toString(produceList.toArray()));

System.out.println("The second list contains[jicama,

potato, banana, grape, squash] "

+

Arrays.toString(foodList.toArray()));

/* un-comment this section if doing the extra credit */

/*

System.out.println(" TESTING EXTRA CREDIT");

AList<Integer> numberListA = new AList<Integer>();

numberListA.add(1);

numberListA.add(5);

numberListA.add(6);

numberListA.add(8);

numberListA.add(7);

numberListA.add(9);

AList<Integer> numberListB = new AList<Integer>();

numberListB.add(2);

numberListB.add(4);

numberListB.add(3);

numberListB.add(9);

numberListB.add(7);

System.out.println("List B is smaller (fewer elements),

result should be positive: " + numberListA.compareTo(numberListB));

numberListA.remove(1);

numberListA.remove(1);

System.out.println("List A is smaller (fewer elements),

result should be negative: " + numberListA.compareTo(numberListB));

numberListA.clear();

numberListA.add(1);

numberListA.add(3);

numberListA.add(5);

numberListA.add(7);

numberListA.add(10);

numberListB.clear();

numberListB.add(2);

numberListB.add(4);

numberListB.add(3);

numberListB.add(9);

numberListB.add(7);

System.out.println("List A is smaller (same number of

elements, 1<2), result should be negative: " +

numberListA.compareTo(numberListB));

numberListB.remove(1);

numberListB.add(1, -2);

Explanation / Answer

If you post more than 1 question, as per chegg guidelines I have to solve only 1 question.

Ques 1.

public int getPosition(T anObject)

{

    // Assuming Node class defines the node

    // head points to the head of the list

    Node<T> trav = head;

   

    int pos = 1;

   

    while( trav != null )

    {

        // getData() returns the value of the node

        if( trav.getData() == anObject )

            return pos;

       

        // move to the next node

        trav = trav.getNext();

       

        pos++;

    }

   

    // if node is not found

    return -1;

}

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