can you check my code why it didnt pass test cases
import java.util.*;
class Node
{
int data;
Node next;
public Node(int n)
{
data=n;
}
}
class Linkedlist
{
Node head;
Node head1;
int count=0;
public void insert(int n)
{
count++;
Node node = new Node(n);
if(head==null)
{
head=node;
}
else
{
Node t=head;
while(t.next!=null)
{
t=t.next;
}
t.next=node;
}
}
int count1=0;
public void insert1(int n)
{
count1++;
Node node = new Node(n);
if(head1==null)
{
head1=node;
}
else
{
Node t=head1;
while(t.next!=null)
{
t=t.next;
}
t.next=node;
}
}
public void merge()
{
Node t=head;
Node n=head1;
Node f=null;
while(t!=null&&n!=null)
{
if(t.data>=n.data)
{
f=add(f,n.data);
n=n.next;
}
else
{
f=add(f,t.data);
t=t.next;
}
}
if(n==null)
{
if(t!=null)
{
while(t!=null)
{
f= add(f,t.data);
t=t.next;
}
}
}
if(t==null)
{
if(n!=null)
{
while(n!=null)
{
f=add(f,n.data);
n=n.next;
}
}
}
while(f!=null)
{
System.out.print(f.data+" ");
f=f.next;
}
}
public Node add(Node f,int d)
{
Node l = new Node(d);
if(f==null)
{
f=l;
}
else
{
Node temp=f;
while(temp.next!=null)
{
temp=temp.next;
}
temp.next=l;
}
return f;
}
}
public class Main {
public static void main(String args[]) {
Linkedlist list = new Linkedlist();
Scanner obj = new Scanner(System.in);
int t=obj.nextInt();
while(t>0)
{
int n=obj.nextInt();
for(int i=0; i<n; i++)
{
int m=obj.nextInt();
list.insert(m);
}
int k=obj.nextInt();
for(int i=0; i<k; i++)
{
int m=obj.nextInt();
list.insert1(m);
}
list.merge();
t–;
}
}
}