Question

Create an ExtArrayList class by extending the ArrayListE> class to include the following methods and estimate the run-time complexity of each method.

1. public ExtArrayList append(ExtArrayList ea)

// appends the values in ea to the end of this ExtArrayList and returns the new ExtArrayList

//example: this: {1,2,3} parameter : {4,5}, result {1,2,3,4,5} 2. public boolean consecutivePair(E e1, E e2)

// checks if this ExtArrayList has two consecutive elements that are equal to e1 and e2 from the

//beginning to the end of the list in that order and returns true, otherwise returns false. You can assume the existence of an appropriately defined equals() method.

// you need to handle errors for different situations.

Create an ExtLinkedList class by extending the LinkedList class to include the following methods and estimate the run-time complexity of each method.

3. public ExtLinkedList evenList()

// gets the elements E in locations 0,2,4,6,… of this list and puts them in a new ExtLinkedList in that order and returns it

// make sure to handle errors 4. public ExtLinkedList intsersect (ExtLinkedList eli)

// picks out elements that are common to this ExtLinkedList and eli // and returns them in the form of a new ExtLinkedList

// once again, you can use equals () method

// the new list should not have duplicate elements // handle errors or exceptional situations appropriately.

// example: this: {1,3,4,4}, parameter : {1,4,5,7} then return {1,4}

Answer 1

The code for the first question related to Create an ExtArrayList class by extending the ArrayListE> class is as follow

import java.util.ArrayList;
import java.util.Arrays;

public class ExtArrayList<E> extends ArrayList {
    /**
     * appending new list to end of the list and return new
     * @param extArrayList
     * @return
     */
    public ExtArrayList append(ExtArrayList extArrayList) {
        // runtime will the O(n) as it will add all data from both array
        // and n will the sum of  size of both array
        if(extArrayList==null){
                throw new NullPointerException(" Values of the array should not be null");
        }else{
            ExtArrayList elements = this;
            elements.addAll(extArrayList);
            return elements;
        }
    }

    /**
     * function to check two consecutive elements
     *
     * @param element1
     * @param element2
     * @return
     */
    public boolean consecutivePair(E element1, E element2) {
        /*
        running time of this function is max O(N)
        and min is O(1) if first two consecutive
        elements are present
         */
        if (element1 == null || element2 == null){
            throw new NullPointerException("value of e1 or e1 cannot be null");
        }
        for (int i = 0; i < this.size(); i++) {
            if (this.get(i).equals(element1)) {
                if (i < this.size() - 1) {
                    if (this.get(i + 1).equals(element2)) {
                        return true;
                    }
                }
            }
        }
        return false;
    }

    @Override
    public boolean equals(Object o) {
        return super.equals(o);
    }
    public static void main(String args[]){
        //creating object ele1 of class
        ExtArrayList<Integer> elem1 = new ExtArrayList<>();
        // Adding the elemets to object created
        elem1.addAll(Arrays.asList(3, 5, 6, 6, 8));
        //creating object ele2 of class
        ExtArrayList<Integer> elem2 = new ExtArrayList<>();
        // Adding the elemets to object created
        elem2.addAll(Arrays.asList(5, 7, 2, 7, 3));
        //combining two ExtArraylist using append method
        ExtArrayList<Integer> merged_array = elem1.append(elem2);
        System.out.println("Merged Array :" + merged_array);
        System.out.print("checking consecutive element (7,3) in ele2 object ");
        System.out.println(elem1.consecutivePair(7, 3));
    }
}

// output

Merged Array :[3, 5, 6, 6, 8, 5, 7, 2, 7, 3]
checking consecutive element (7,3) in ele2 object true

The time complexity is written as a comment in function only.

I hope you understand the code and got the answer.

Kindly ask the question of creating an ExtLinkedList class by extending the LinkedList class to include the following methods, as it is another question.

I hope you understand it and Thank you:):)