Design and implement a getLastHalf() method for the MyLinkedList class. The method should return the last half of the list as a new list leaving the original list intact. If the list has an uneven number of elements the extra one element must be in the list returned.
Design and implement a getLastHalf() method for the MyLinkedList class. The method should return the last half of the list as a new list leaving the original list intact. If the list has an uneven number of elements the extra one element must be in the list returned.
Example : [1,3,5,4] return [5,4] and [1,6,9] return [6,9].
Follow the three step method for designing the method
Develop the java code for the method
Create a test program to test the method thoroughly using the Integer wrapper class.
public class MyLinkedList<E> { private Node<E> head, tail; public MyLinkedList() { head = null; tail = null; } /** Return the head element in the list */ public E getFirst() { if (head == null) { return null; } else { return head.element; } } /** Return the last element in the list */ public E getLast() { if (head==null) { return null; } else { return tail.element; } } /** Add an element to the beginning of the list */ public void prepend(E e) { Node<E> newNode = new Node<>(e); // Create a new node newNode.next = head; // link the new node with the head head = newNode; // head points to the new node if (tail == null) // the new node is the only node in list tail = head; } /** Add an element to the end of the list */ public void append(E item) { Node<E> newNode = new Node<>(item); // Create a new for element e if (head == null) { head = tail = newNode; // The new node is the only node in list } else { tail.next = newNode; // Link the new with the last node tail = newNode; // tail now points to the last node } } /** Remove the head node and * return the object that is contained in the removed node. */ public E removeFirst() { if (head == null) { return null; } else { E temp = head.element; head = head.next; if (head == null) { tail = null; } return temp; } } public boolean delete(E item) { Node<E> ptr = head; Node<E> prvPtr = null; while (ptr!= null&& ((Comparable)ptr.element).compareTo(item)!= 0) { prvPtr=ptr; ptr=ptr.next; } if (ptr == null)//item not found return false; if (ptr==head) // item is first element head= head.next; else // general case prvPtr.next=ptr.next; if (ptr==tail)// last element tail=prvPtr; return true; } public String toString() { String result = "["; Node<E> ptr = head; for (ptr= head;ptr!=null; ptr=ptr.next) { result = result + ptr.element.toString(); if (ptr.next != null) result = result + ","; // add commas but not to the final 1 } result += "]"; // Insert the closing ] in the string return result; } public void clear() { head = tail = null; } private static class Node<E> { E element; Node<E> next; public Node(E element) { this.element = element; next = null; } } } // end myLinkedList class
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