In the Assignment #10, you are given three files Assignment10.java, LinkedList.j

Question

In the Assignment #10, you are given three files Assignment10.java, LinkedList.java, and ListIterator.java. You will need to add additional methods in the LinkedList class in the LinkedList.java file. The LinkedList will be tested using strings only.

Specifically, the following methods must be implemented in the LinkedList class:
(You should utilize listIterator() method already defined in the LinkedList class to obtain its LinkedListIterator object, and use the methods in the LinkedListIterator class to traverse from the first element to the last element of the linked list to define the following methods.)

1.
    public String toString()

The toString method should concatenate strings in the linked list, and return a string of the following format:

{ Apple Melon Orange Banana }

Thus it starts with "{" and ends with "}", and there is a space between strings and "{" or "}". If the list is empty, it returns "{ }" with a space in between.

2.
    public int size()

The size method returns the number of strings that the linked list contains at the time when this method is called.

3.
    public void addElement(Object element, int index)

The addElement adds the parameter element at the parameter specified index. The element at the index and any elements at the later indices will be shifted towards the end of the list. If the parameter index is larger or smaller than the existing indices, it should throw an object of the IndexOutOfBoundsException class.

4.
    public String findSmallest( )

The findSmallest method should return the string that is smallest lexically among the strings stored in the linked list. It should return null (null pointer) if the linked list is empty.

5.
    public void searchAndReplace(Object first, Object second)

The searchAndReplace method should search and replace all strings that match with the first parameter "first" with the second parameter "second". If the linked list does not contain a string that matches with the first parameter, then the linked list content should not change after calling this method.

6.
    public void searchAndRemove(Object toBeRemoved)

The searchAndRemove method should search and remove all strings that match with the first parameter "toBeRemoved". If the linked list does not contain a string that matches with the first parameter, then the linked list content should not change after calling this method.

7.
    public void reverseFirstSome(int howMany)

The reverseFirstSome method should reverse the number of strings located at the beginning, specified by the parameter integer. For instance, if the parameter "howMany" is 3, then the first 3 strings in the linked list should be reversed.
If the number "howMany" is 0 or less, then the linked list content will not change, and if it is same or more than the size of the linked list, then the entire linked list content will be reversed.

(This file does not need to be modified)

(This file does not need to be modified)

(It needs to be modified)

input 1:
A
Grape
0
L
A
Melon
0
L
C
A
Apple
2
L
A
Peach
0
L
A
Banana
1
L
C
D
L
A
Potato
-1
L
A
Kiwi
5
L
A
Avocado
10
L
A
Lemon
0
L
Q

input 2:
L
C
A
Banana
10
L
A
Apple
0
L
A
Potato
1
A
Grape
2
A
Melon
0
A
Kiwi
1
A
Lemon
2
A
Guava
3
A
Orange
2
A
Olive
3
A
Pear
4
L
T
3
L
T
5
L
T
-3
L
T
1000
L
Q

input 3:
C
R
Orange
Apple
L
S
Orange
L
A
Apple
6
L
A
Orange
0
A
Tomato
1
A
Apple
0
A
Potato
1
A
Orange
2
L
R
Orange
Kiwi
L
R
Kiwi
Lemon
L
R
Tomato
Potato
L
R
Potato
Watermelon
L
S
Apple
L
C
Q

input 4:
L
D
C
A
Tomato
0
A
Mango
0
A
Banana
2
A
Guava
2
L
C
D
A
Lime
2
L
R
Apple
Tomato
L
R
Lime
Guava
L
S
Guava
L
Q

output 1:
Choice       Action
------       ------
A       Add String
C       Count its Size
D       Find Smallest
L       List Strings
Q       Quit
R       Replace Strings
S       Remove Strings
T       Reverse Strings from Beginning
?       Display Help

What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Grape }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Melon Grape }
What action would you like to perform?
The size of the linked list is 2
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Melon Grape Apple }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Peach Melon Grape Apple }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Peach Banana Melon Grape Apple }
What action would you like to perform?
The size of the linked list is 5
What action would you like to perform?
The smallest string is Apple
What action would you like to perform?
{ Peach Banana Melon Grape Apple }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
The index is out of bounds
What action would you like to perform?
{ Peach Banana Melon Grape Apple }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Peach Banana Melon Grape Apple Kiwi }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
The index is out of bounds
What action would you like to perform?
{ Peach Banana Melon Grape Apple Kiwi }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Lemon Peach Banana Melon Grape Apple Kiwi }
What action would you like to perform?

output 2:
Choice       Action
------       ------
A       Add String
C       Count its Size
D       Find Smallest
L       List Strings
Q       Quit
R       Replace Strings
S       Remove Strings
T       Reverse Strings from Beginning
?       Display Help

What action would you like to perform?
{ }
What action would you like to perform?
The size of the linked list is 0
What action would you like to perform?
Please enter a string to add:
Please enter its index:
The index is out of bounds
What action would you like to perform?
{ }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Apple }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Melon Kiwi Orange Olive Pear Lemon Guava Apple Potato Grape }
What action would you like to perform?
Please enter a number of elements to reverse from the beginning:
What action would you like to perform?
{ Orange Kiwi Melon Olive Pear Lemon Guava Apple Potato Grape }
What action would you like to perform?
Please enter a number of elements to reverse from the beginning:
What action would you like to perform?
{ Pear Olive Melon Kiwi Orange Lemon Guava Apple Potato Grape }
What action would you like to perform?
Please enter a number of elements to reverse from the beginning:
What action would you like to perform?
{ Pear Olive Melon Kiwi Orange Lemon Guava Apple Potato Grape }
What action would you like to perform?
Please enter a number of elements to reverse from the beginning:
What action would you like to perform?
{ Grape Potato Apple Guava Lemon Orange Kiwi Melon Olive Pear }
What action would you like to perform?

output 3:
Choice       Action
------       ------
A       Add String
C       Count its Size
D       Find Smallest
L       List Strings
Q       Quit
R       Replace Strings
S       Remove Strings
T       Reverse Strings from Beginning
?       Display Help

What action would you like to perform?
The size of the linked list is 0
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ }
What action would you like to perform?
Please enter a string to remove from the linked list:
What action would you like to perform?
{ }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
The index is out of bounds
What action would you like to perform?
{ }
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Apple Potato Orange Orange Tomato }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Apple Potato Kiwi Kiwi Tomato }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Apple Potato Lemon Lemon Tomato }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Apple Potato Lemon Lemon Potato }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Apple Watermelon Lemon Lemon Watermelon }
What action would you like to perform?
Please enter a string to remove from the linked list:
What action would you like to perform?
{ Watermelon Lemon Lemon Watermelon }
What action would you like to perform?
The size of the linked list is 4
What action would you like to perform?

output 4:
Choice       Action
------       ------
A       Add String
C       Count its Size
D       Find Smallest
L       List Strings
Q       Quit
R       Replace Strings
S       Remove Strings
T       Reverse Strings from Beginning
?       Display Help

What action would you like to perform?
{ }
What action would you like to perform?
There is no element in the linked list
What action would you like to perform?
The size of the linked list is 0
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Mango Tomato Guava Banana }
What action would you like to perform?
The size of the linked list is 4
What action would you like to perform?
The smallest string is Banana
What action would you like to perform?
Please enter a string to add:
Please enter its index:
What action would you like to perform?
{ Mango Tomato Lime Guava Banana }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Mango Tomato Lime Guava Banana }
What action would you like to perform?
Please enter a string to replace from the linked list:
Please enter a string to replace with:
What action would you like to perform?
{ Mango Tomato Guava Guava Banana }
What action would you like to perform?
Please enter a string to remove from the linked list:
What action would you like to perform?
{ Mango Tomato Banana }
What action would you like to perform?

Assignment 10 +main(StringO): void printMenuo void LinkedList first Node +LinkedList() getFirst(): Object tremove First(): Object +addFirst object): void rtlistlteratoro: Listlterator +toString (0:String size():int +addElement(Object, int) void tfindSmallesto:String searchAndReplace(Object,Object):void tsearchAndRemove(Object):void +reversed FirstSome(int) void You will need to implement only the methods in red. LinkedListIterator position: Node -previous: Node +LinkedListlterator0 +has Next():boolean +next0: Object +add(Object): void +remove(): void +set (Object):void Node data: Object +next:Node Arizona State University CSE205, Assignment 10, Spring 2017 ListIterator +has Nexto: boolean +next(0:Object +add(Object): void +remove(): void +set objecto void

Explanation / Answer

import java.util.NoSuchElementException; /* Class linkedList */ class LinkedList { //nested class to represent a node private class Node { public Object data; public Node next; } //only instance variable that points to the first node. private Node first; // Constructs an empty linked list. public LinkedList() { first = null; } public void addElement(String str1, int index) throws IndexOutOfBoundsException { if (size() 0) { temp = (Node) i.next(); index--; } Node node = new Node(); node.data = str1; node.next = temp.next; temp.next = node; } public int size() { if (first == null) { return 0; } int size = 0; ListIterator i = listIterator(); while (i.hasNext()) { i.next(); size++; } return size; } public String findSmallest() { if (first == null) { return null; } String smallest = (String) first.data; Node temp = first.next; ListIterator i = listIterator(); while (i.hasNext()) { temp = (Node) i.next(); if (((String) temp.data).compareTo(smallest) == -1) { smallest = (String) temp.data; } } return smallest; } public void searchAndReplace(String first, String second) { ListIterator i = listIterator(); while (i.hasNext()) { Node temp = (Node) i.next(); if (((String) temp.data).equals(first)) { temp.data = second; return; } } } public void searchAndRemove(String inputInfo) { ListIterator i = listIterator(); Node prev = first; while (i.hasNext()) { Node temp = (Node) i.next(); if (((String) temp.data).equals(inputInfo)) { prev.next = temp.next; temp = null; return; } prev = temp; } } public void reverseFirstSome(int howMany) { ListIterator i = listIterator(); Node prev = null; Node curr = first; while (i.hasNext() && howMany > 0) { Node temp = (Node) i.next(); // Node node = temp.next; curr.next = prev; prev = curr; curr = temp; howMany--; } } // Returns the first element in the linked list. public Object getFirst() { if (first == null) { NoSuchElementException ex = new NoSuchElementException(); throw ex; } else return first.data; } // Removes the first element in the linked list. public Object removeFirst() { if (first == null) { NoSuchElementException ex = new NoSuchElementException(); throw ex; } else { Object element = first.data; first = first.next; //change the reference since it's removed. return element; } } // Adds an element to the front of the linked list. public void addFirst(Object element) { //create a new node Node newNode = new Node(); newNode.data = element; newNode.next = first; //change the first reference to the new node. first = newNode; } // Returns an iterator for iterating through this list. public ListIterator listIterator() { return new LinkedListIterator(); } //nested class to define its iterator private class LinkedListIterator implements ListIterator { private Node position; //current position private Node previous; //it is used for remove() method // Constructs an iterator that points to the front // of the linked list. public LinkedListIterator() { position = null; previous = null; } // Tests if there is an element after the iterator position. public boolean hasNext() { if (position == null) //not traversed yet { if (first != null) return true; else return false; } else { if (position.next != null) return true; else return false; } } // Moves the iterator past the next element, and returns // the traversed element's data. public Object next() { if (!hasNext()) { NoSuchElementException ex = new NoSuchElementException(); throw ex; } else { previous = position; // Remember for remove if (position == null) position = first; else position = position.next; return position.data; } } // Adds an element after the iterator position // and moves the iterator past the inserted element. public void add(Object element) { if (position == null) //never traversed yet { addFirst(element); position = first; } else { //making a new node to add Node newNode = new Node(); newNode.data = element; newNode.next = position.next; //change the link to insert the new node position.next = newNode; //move the position forward to the new node position = newNode; } //this means that we cannot call remove() right after add() previous = position; } // Removes the last traversed element. This method may // only be called after a call to the next() method. public void remove() { if (previous == position) //not after next() is called { IllegalStateException ex = new IllegalStateException(); throw ex; } else { if (position == first) { removeFirst(); } else { previous.next = position.next; //removing } //stepping back //this also means that remove() cannot be called twice in a row. position = previous; } } // Sets the last traversed element to a different value. public void set(Object element) { if (position == null) { NoSuchElementException ex = new NoSuchElementException(); throw ex; } else position.data = element; } } //end of LinkedListIterator class }

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---