Instead of a String[] it must use a Doubly-Linked List with a Dummy Front and Dummy Rear to store the List's data. How do I change that in my class list?

The List class' public API is the same except:

(1) Constructor List(int size) has been replaced with List(). The Linked-List has no maximum size.

(2) Constructor List(List list) has been added. It constructs a new List with the items in the input list.

//main:

public class AssignmentFour { public static void main(String[] args) { List myList = new List(); List emptyList = new List(myList); // Cause List Empty Message myList.removeFront(); myList.removeRear(); myList.removeItem("a"); // Cause Not found message myList.addToFront("x"); myList.removeItem("y"); myList.removeItem("x"); myList.addAfterItem("x", "z"); myList.addBeforeItem("x", "z"); // Normal behavior myList.addToFront("not."); myList.addToFront("or"); myList.addToRear("is"); myList.addToRear("try."); myList.addAfterItem("is", "no"); myList.addBeforeItem("is", "There"); myList.addToFront("Do"); myList.addAfterItem("or", "do"); myList.print("Original list"); myList.printSorted("Sorted Original List"); emptyList.print("Empty List"); List copyOfList = new List(myList); sop(" Front is " + myList.getFront()); sop("Rear is " + myList.getRear()); sop("Count is " + myList.askCount()); sop("Is There present? " + myList.isPresent("There")); sop("Is Dog present? " + myList.isPresent("Dog")); myList.addToFront("junk"); myList.addToRear("morejunk"); myList.addAfterItem("or", "moremorejunk"); myList.print("List with junk"); sop("Count is " + myList.askCount()); copyOfList.print("Untouched copy of the list"); myList.removeFront(); myList.removeRear(); myList.removeItem("moremorejunk"); myList.print("List with junk removed"); sop("Count is " + myList.askCount()); sop(""); copyOfList.print("Untouched copy of the list"); while(myList.askCount() > 0) myList.removeFront(); myList.print("List after removing all items"); copyOfList.print("Copy of List after removing all items"); } private static void sop(String s) { System.out.println(s); } }

//My class list:

import java.util.Arrays;

public class List { private String[] mList; private int mCount; public List(int size) { mCount = 0; mList = new String[size]; } public void addToFront(java.lang.String item) { if (mCount == mList.length) { System.out.println("List Full"); } else if (mCount == 0) { mList[0] = item; mCount++; } else { shiftRight(mCount,0); mList[0] = item; mCount++; } } public void addToRear(java.lang.String item) { if (mCount == mList.length) { System.out.println("List Full"); } else { mList[mCount++] = item; } } public void addBeforeItem(java.lang.String beforeItem, java.lang.String item) { if (mCount == mList.length) { System.out.println("List Full"); } else if(isPresent(beforeItem) && mCount < mList.length) { if (find(beforeItem) == 0) { shiftRight(mCount,0); mList[0] = item; mCount++; } else { shiftRight(mCount,find(beforeItem)); mList[find(beforeItem)] = item; mCount++; } } else if(!isPresent(beforeItem)) { System.out.println("Item not found"); } } //Finding the index of the specific element private int find (String s) { for(int i = 0; i < mCount;i++) { if (mList[i].equals(s)) { return i; } } return -1; } public void addAfterItem(java.lang.String afterItem, java.lang.String item) { if (mCount == mList.length) { System.out.println("List Full"); } else if(isPresent(afterItem) && mCount < mList.length) { shiftRight(mCount, find(afterItem)); mList[find(afterItem)+1] = item; mCount++; } else { System.out.println("Item not found"); } } public java.lang.String getFront() { return mList[0]; } public java.lang.String getRear() { return mList[mCount-1]; } public boolean isPresent(String item) { for (int i = 0; i < mCount; i++) if(mList[i].equals(item)) { return true; } return false; } public int askCount() { return mCount; } public void removeFront() { if (mCount == 0) { System.out.println("List Empty"); } else { shiftLeft(mCount, 0); mCount--; } } public void removeRear() { if (mCount == 0) { System.out.println("List Empty"); } else { mCount--; } } public void removeItem(java.lang.String item) { if (mCount == 0) { System.out.println("List Empty"); } else if (!isPresent(item)) { System.out.println("Item not found"); } else { int x = find(item); shiftLeft(mCount,x); mCount--; } } public void print(java.lang.String title) { System.out.println(""); System.out.println(title); for(int i = 0; i < mCount; i++) { System.out.print(mList[i] + " "); } System.out.println(); } public void printSorted(java.lang.String title) { String[] mListC = new String[mCount]; System.arraycopy( mList, 0,mListC, 0, mCount); Arrays.sort(mListC); System.out.println(); System.out.println(title); for(String s : mListC) { System.out.print(s + " "); } System.out.println(); } private void shiftRight(int count, int end) { for (int i = (count-1); i >= end; i--) { mList[i+1] = mList[i]; } } private void shiftLeft(int count, int start) { for (int i = start;i < count-1; i++) { mList[i] = mList[i+1]; } } }

// Desired Output:

List Empty List Empty List Empty Item not found Item Not Found Item Not Found Original list Do or do not. There is no try. Sorted Original List Do There do is no not. or try. Empty List Front is Do Rear is try. Count is 8 Is There present? true Is Dog present? false List with junk junk Do or moremorejunk do not. There is no try. morejunk Count is 11 Untouched copy of the list Do or do not. There is no try. List with junk removed Do or do not. There is no try. Count is 8 Untouched copy of the list Do or do not. There is no try. List after removing all items Copy of List after removing all items Do or do not. There is no try.