Generics All of the classes in the Java Colections Framework (JCF) use generics.

Question

Generics All of the classes in the Java Colections Framework (JCF) use generics. As we saw w ith the cosparable interface, one purpose of this is that it lats us specify w hich type of objects we are deaing w ith (we can think of the class as having a parameter that spec?ies a type inside it). Note that w hen using generics we can only use reference data types. Java does not alow us to use primitive data types w ith generics (and this is one very good reason we have the primitive w rapper classes). We w ill cover generics in more detail in class later ArrayList The arraylist is a commorly used class in the the JCF It implements the list abstract data type (ADT) https:docs.oracle.comjavase/8idocs/apijavali ArrayList.hm Open up a web brow ser and see what methods the ArrayList class provides. In particular, look at add(E eadint index, E e) get(int index), renove(int index), set(int index, E e?, and size(). Note, E is the type you specify when creating the ArrayList (as follow s) isport java.uts.Arraylist eapty string 1ist ( is String here) ArrayListeString slist new ArraylisteStrin0 eapty integer list (E is Integer here)* ArrayListeinteger ilist new ArrayListeinteger> Modiy your TesELL program so that for each linked list in the program you have a mirror list that is an ArrayList. Use the same operations (w hen applcable) to create the ArrayLists. 2. Overload the sase method to take an LList and an ArraylisteString> that checks if tw o lists are the same.

Explanation / Answer

import java.util.ArrayList;

import java.util.Iterator;

import java.util.LinkedList;

public class TestLL {

public static void main(String[] args) {

// create an empty linked list

LinkedList<String> list = new LinkedList<String>();

System.out.print("empty list : ");

System.out.println(list);

// create a list with one element

// list = [cat]

list.add("cat");

System.out.print("singleton : ");

System.out.println(list);

// add some elements to the back and front

list.addFirst("dog");

list.addFirst("owl");

list.addLast("bat");

System.out.print("some adds : ");

System.out.println(list);

// abritrary adds

try {

list.add(1, "crow");

} catch (IndexOutOfBoundsException e) {

System.out.println(e);

}

try {

list.add(1, "goat");

} catch (IndexOutOfBoundsException e) {

System.out.println(e);

}

try {

list.add(2, "eel");

} catch (IndexOutOfBoundsException e) {

System.out.println(e);

}

System.out.print("more adds : ");

System.out.println(list);

// some gets

System.out.println("x0 = " + list.get(0));

System.out.println("x1 = " + list.get(1));

System.out.println("x5 = " + list.get(5));

System.out.println("xn = " + list.get(list.size() - 1));

// removes

list.removeFirst();

list.removeFirst();

System.out.println("removes : " + list);

// removes

list.remove(3);

list.remove(list.size() - 1);

System.out.println("removes : " + list);

// remove front add to back

System.out.println("before : " + list);

System.out.println("move front to back ");

list.addLast(list.removeFirst());

System.out.println("after : " + list);

// Array list with mirror elements as LinkedList list

ArrayList<String> alist = new ArrayList<String>();

for (String s : list) {

alist.add(0, s);

}

System.out.println("Linked List list= " + list);

System.out.println("Mirror of Linked List list =" + alist);

LinkedList<String> l1 = new LinkedList<String>();

l1.add("a");

ArrayList<String> l2 = new ArrayList<String>();

l2.add("a");

try {

l1.addFirst("b");

l1.addLast("c");

l1.add("d");

l1.addFirst("b");

l1.addLast("c");

l1.add("eeee");

} catch (IndexOutOfBoundsException e) {

System.out.println(e);

}

// Array list with mirror elements as LinkedList l1

ArrayList<String> alist1 = new ArrayList<String>();

for (String s : l1) {

alist1.add(0, s);

}

System.out.println("Linked List l1= " + l1);

System.out.println("Mirror of Linked List l1 =" + alist1);

// System.out.println("l1.compareTo(l2) = " + l1.c l1.compareTo(l2));

// uncomment this next line

System.out.println("same(l1,l2) = " + same(l1, l2));

}

public static boolean same(LinkedList<String> ll, ArrayList<String> al) {

int flag = 0;

if (ll.size() != al.size())

return false;

int i = al.size();

Iterator<String> itr = al.iterator();

while (itr.hasNext()) {

String str = itr.next();

if (!str.equals(ll.get(i)))

flag = -1;

}

if (flag == -1)

return false;

else

return true;

}

}

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