LL.java

public class LL<E>{
    private static class Node<E>{
        E data;
        Node<E> next;
        public Node(E data, Node<E> next){
            this.data = data;
            this.next = next;
        }
        public Node(E data){
            this.data = data;
            this.next = null;
        }
        public void append(E elem){
            Node<E> t = this;
            while(t.next != null)
                t = t.next;
            t.next = new Node<>(elem);
        }
        public Node<E> append(Node<E> n){
            Node<E> t = this;
            while(t.next != null)
                t = t.next;
            t.next = n;
            return this;
        }
        public String toString(){
            Node<E> t = this;
            String out = "[ ";
            while(t!= null){
                out += t.data.toString() + " ";
                t=t.next;
            }
            return out + "]";
        }
    }

    public static <E> Node<E> iter_repeatLN(Node<E> node, int n){
        Node<E> out = new Node<>(node.data);
        for(int i = 0; i < n; i++){
            Node<E> cur = node;
            while(cur != null){
                out.append(cur.data);
                cur = cur.next;
            }
        }
        return out.next;
    }

    public static <E> Node<E> rec_repeatLN(Node<E> node, int n){
        Node<E> out = new Node<>(node.data);
        Node<E> t = node;
        while(t.next != null){
            out.append(t.next.data);
            t = t.next;
        }
        if(n == 0)
            return null;
        return out.append(rec_repeatLN(node, n-1));
    }
    public static void main(String[] args){
        Node<Integer> n = new Node<>(1);
        n.append(2);
        n.append(3);
        System.out.println(n);
        System.out.println(rec_repeatLN(n, 3));

    }
}