Linked list insertion

//Linked list insertion

import java.util.*;
import java.io.*;

class Node{
    int data;
    Node next;
    
    Node(int x){
        data = x;
        next = null;
    }
}

class GFG {
    static void printList(Node node) {
        while (node != null) { 
            System.out.print(node.data + " "); 
            node = node.next; 
        } 
        System.out.println(); 
    }

    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();
            Node head = null;

            for(int i=0; i<n; i++) {
                int value = sc.nextInt();
                int indicator = sc.nextInt();
                Solution ob = new Solution();

                if(indicator == 0)
                    head = ob.insertAtBeginning(head, value);
                else
                    head = ob.insertAtEnd(head, value);
            }

            printList(head); 
            t--;
        }
    } 
} 

class Node{
    int data;
    Node next;
    
    Node(int x){
        data = x;
        next = null;
    }
}

class Solution {
    Node insertAtBeginning(Node head, int x) {
        Node newNode = new Node(x);
        newNode.next = head;
        head = newNode;
        
        return head;
    }

    Node insertAtEnd(Node head, int x) {
        Node newNode = new Node(x);
        
        if(head == null) {
            return newNode;
        }
        
        Node curr = head;
        
        while(curr.next != null) {
            curr = curr.next;
        }
        
        curr.next = newNode;
        
        return head;
    }
}