SinglyLLAnyType (1).java

class Node<T> {
    T data;
    Node<T> next;

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

class LinkedListADT<T> {
    private Node<T> head;

    public LinkedListADT() {
        this.head = null;
    }

    public boolean isEmpty() {
        return head == null;
    }

    public void insertAtFront(T data) {
        Node<T> newNode = new Node<>(data);
        if (isEmpty()) {
            head = newNode;
        } else {
            newNode.next = head;
            head = newNode;
        }
    }

    public void insertAtEnd(T data) {
        Node<T> newNode = new Node<>(data);
        if (isEmpty()) {
            head = newNode;
        } else {
            Node<T> current = head;
            while (current.next != null) {
                current = current.next;
            }
            current.next = newNode;
        }
    }

    public void insertAtIndex(T data, int index) {
        if (index < 0 || index > getSize()) {
            System.out.println("Invalid index");
            return;
        }

        if (index == 0) {
            insertAtFront(data);
            return;
        }

        Node<T> newNode = new Node<>(data);
        Node<T> current = head;
        int count = 0;

        while (count < index - 1) {
            current = current.next;
            count++;
        }

        newNode.next = current.next;
        current.next = newNode;
    }

    public void deleteAtFront() {
        if (isEmpty()) {
            System.out.println("Linked list is empty");
        } else {
            head = head.next;
        }
    }

    public void deleteAtEnd() {
        if (isEmpty()) {
            System.out.println("Linked list is empty");
        } else if (head.next == null) {
            head = null;
        } else {
            Node<T> current = head;
            Node<T> previous = null;
            while (current.next != null) {
                previous = current;
                current = current.next;
            }
            previous.next = null;
        }
    }

    public void deleteAtIndex(int index) {
        if (index < 0 || index >= getSize()) {
            System.out.println("Invalid index");
            return;
        }

        if (index == 0) {
            deleteAtFront();
            return;
        }

        Node<T> current = head;
        int count = 0;

        while (count < index - 1) {
            current = current.next;
            count++;
        }

        current.next = current.next.next;
    }

    public boolean search(T data) {
        Node<T> current = head;
        while (current != null) {
            if (current.data.equals(data)) {
                return true;
            }
            current = current.next;
        }
        return false;
    }

    public int getSize() {
        int count = 0;
        Node<T> current = head;
        while (current != null) {
            count++;
            current = current.next;
        }
        return count;
    }

    public void display() {
        if (isEmpty()) {
            System.out.println("Linked list is empty");
        } else {
            Node<T> current = head;
            while (current != null) {
                System.out.print(current.data + " ");
                current = current.next;
            }
            System.out.println();
        }
    }
}

public class MainAnyType {
    public static void main(String[] args) {
        LinkedListADT<Integer> integerList = new LinkedListADT<>();
        integerList.insertAtFront(3);
        integerList.insertAtFront(2);
        integerList.insertAtFront(1);

        integerList.display(); // Output: 1 2 3

        LinkedListADT<String> stringList = new LinkedListADT<>();
        stringList.insertAtEnd("World");
        stringList.insertAtFront("Hello");
		
		stringList.display(); // Output: Hello World
		
		LinkedListADT<Object> anyList = new LinkedListADT<>();
        anyList.insertAtEnd('N');
		anyList.insertAtIndex('R', 1);
		anyList.insertAtIndex(10, 2);
        anyList.insertAtFront("Hello");

        anyList.display(); // Output: Hello N R 10 
    }
}