My Linked List

Implement a class named MyLinkedList that represents a mutable list of integers.

You only need to implement the required class, constructor, and methods. Do not read input and do not print output. The grading system will provide a hidden wrapper that creates your object and calls your methods.

Required class

public class MyLinkedList {
    public MyLinkedList();
    public void addFirst(int value);
    public void addLast(int value);
    public int get(int index);
    public int remove(int index);
    public int size();
}

Method requirements

MyLinkedList()

Creates an empty list.

void addFirst(int value)

Adds value to the beginning of the list.

Example:

Current list: [10, 20]
addFirst(5)
Result:       [5, 10, 20]

void addLast(int value)

Adds value to the end of the list.

Example:

Current list: [10, 20]
addLast(30)
Result:       [10, 20, 30]

int get(int index)

Returns the value at the given 0-based index.

If index < 0 or index >= size(), return -1.

Example:

List:   [5, 10, 20]

get(0)  -> 5
get(2)  -> 20
get(3)  -> -1
get(-1) -> -1

int remove(int index)

Removes the element at the given 0-based index and returns the removed value.

If the index is invalid, do not modify the list and return -1.

Example:

List: [5, 10, 20]

remove(1) -> 10

List becomes:
[5, 20]

int size()

Returns the current number of elements in the list.

Requirements

• The list is initially empty.
• Indices are 0-based.
• The object must preserve its state across multiple method calls.
• Invalid get and remove operations must return -1.
• Submit only the MyLinkedList class.
• Do not implement input parsing or output printing.
• A main() method is not required.

Example behavior

Suppose the grading system performs:

Create a new MyLinkedList
addLast(10)
addLast(20)
addFirst(5)
size()
get(0)
get(1)
get(2)
remove(1)
size()

The returned values are:

3
5
10
20
10
2

The final list is:

[5, 20]

Submission template

public class MyLinkedList {

    public MyLinkedList() {
        // your code
    }

    public void addFirst(int value) {
        // your code
    }

    public void addLast(int value) {
        // your code
    }

    public int get(int index) {
        // your code
        return -1;
    }

    public int remove(int index) {
        // your code
        return -1;
    }

    public int size() {
        // your code
        return 0;
    }
}