Linked list

//Linked list

import java.util.*;
import java.lang.*;
import java.math.*;
import java.io.*;

class Node { 
    int data; 
    Node next; 

    Node() { data = 0; }
    Node(int d) { data = d; }
} 

class GFG {
    public static void main(String[] args) throws IOException {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();

        while(T-- > 0) {
            int n = sc.nextInt();
            int a[] = new int[n];

            for(int i = 0; i < n; i++)
                a[i] = sc.nextInt();

            Solution obj = new Solution();
            Node ans = obj.constructLL(a);
            while(ans != null) {
                System.out.print(ans.data + " ");
                ans = ans.next;
            }
            System.out.println();
        }
    }
}

class Node { 
    int data; 
    Node next; 

    Node() { data = 0; }
    Node(int d) { data = d; }
}

class Solution {
    static Node constructLL(int arr[]) {
        Node head = new Node(arr[0]);
        Node curr = head;
        
        for(int i = 1; i < arr.length; i++) {
            Node newNode = new Node(arr[i]);
            curr.next = newNode;
            curr = curr.next;
        }
        
        return head;
    }
}