Bubble Sort Using a Linked List

class Node {
    int data;
    Node next;

    public Node(int data) {
        this.data = data;
        this.next = null;
    }
}

public class BubbleSortLinkedList {
    Node head;

    public void insert(int data) {
        Node newNode = new Node(data);
        if (head == null) {
            head = newNode;
        } else {
            Node current = head;
            while (current.next != null) {
                current = current.next;
            }
            current.next = newNode;
        }
    }

    public void bubbleSort() {
        if (head == null || head.next == null) {
            return;
        }
        boolean swapped;
        do {
            swapped = false;
            Node current = head;
            Node prev = null;
            while (current.next != null) {
                if (current.data > current.next.data) {
                    Node temp = current.next;
                    current.next = temp.next;
                    temp.next = current;
                    if (prev == null) {
                        head = temp;
                    } else {
                        prev.next = temp;
                    }
                    prev = temp;
                    swapped = true;
                } else {
                    prev = current;
                    current = current.next;
                }
            }
        } while (swapped);
    }

    public void display() {
        Node current = head;
        while (current != null) {
            System.out.print(current.data + " ");
            current = current.next;
        }
        System.out.println();
    }

    public static void main(String[] args) {
        BubbleSortLinkedList list = new BubbleSortLinkedList();
        list.insert(34);
        list.insert(10);
        list.insert(64);
        list.insert(51);
        list.insert(32);
        list.insert(21);

        System.out.println("Original linked list:");
        list.display();

        list.bubbleSort();

        System.out.println("Linked list after Bubble Sort:");
        list.display();
    }
}