import java.util.Arrays;
class Node {
String value;
Node next;
}
class LinkedList {
private Node head;
private Node tail;
private int length;
public LinkedList(int value) {
head = new Node(value);
tail = head;
length = 1;
}
public void prepend(int value) {
Node newNode = new Node(value);
head.next = head;
head = newNode;
length++;
}
public void append(int value) {
Node newNode = new Node(value);
tail.next = newNode;
tail = newNode;
length++;
}
public int getLength() {
return length;
}
public int[] printList() {
int[] myList = new int[length];
Node current = this.head;
int i = 0;
while(current != null) {
myList[i] = current.value;
current = current.next;
i++;
}
return myList;
}
public void insert(int index, int value) {
if(index < 0 || index > length) {
System.out.println("Index out of bounds for length " + length);
}
else if(index == 0) {
prepend(value);
}
else if(index == length) {
append(value);
}
else {
Node current = head;
for(int i = 0; i < index - 1; i++) {
current = current.next;
}
Node newNode = new Node(value);
newNode.next = current.next;
current.next = newNode;
length++;
}
}
public void remove(int index) {
if( index < 0 || index > length) {
System.out.println("Index out of bounds for length " + length);
}
else if(index == 0) {
head = this.head.next;
length--;
}
else {
Node current = head;
int i;
for(i = 0; i < index - 1; i++) {
current = current.next;
}
current.next = current.next.next;
length--;
if(i = length - 1) {
tail = current;
}
}
}
public LinkedList reverse(LinkedList linkedList) {
LinkedList newList = new LinkedList(linkedList.head.value);
Node current = linkedList.head;
while(current.next != null) {
current = current.next;
Node newNode = newNode(current.value);
newNode.next = newList.head;
newList.head = newNode;
newList.length++;
}
return newList;
}
public static void main(String[] args) {
System.out.println("Hello World!");
LinkedList myLinkedList = new LinkedList(10);
//append
myLinkedList.append(12);
myLinkedList.append(16);
//prepend
myLinkedList.prepend(20);
myLinkedList.prepend(50);
System.out.println("length: " + myLinkedList.getLength());
System.out.println("list: " + Arrays.toString(myLinkedList.printList()));
//insert
myLinkedList.insert(2, 25);
System.out.println("length: " + myLinkedList.getLength());
System.out.println("list: " + Arrays.toString(myLinkedList.printList()));
//remove
myLinkedList.remove(4);
System.out.println("length: " + myLinkedList.getLength());
System.out.println("list: " + Arrays.toString(myLinkedList.printList()));
//reverse
LinkedList linkedList2 = myLinkedList.reverse(myLinkedList);
System.out.println("reverse linkedList" + Arrays.toString(linkedList2.printList()));
}
}
