SINGLY LINKED LIST IN JAVA

/*
TOPIC: SINGLY LINKED LIST
DATE:30/8/2012

*/
import java.io.*;
class node
{
int data;
node next;
public node(int k)
{
data=k;
next=null;
}
}
class LinkedList
{
node start=null;
public boolean empty()
{
if(start==null)
return true;
else return false;
}
public void create(int n)throws Exception
{
node p,q;
for(int i=0;i<n;i++)
{
DataInputStream in=new DataInputStream(System.in);
System.out.println("Enter the DAta::=");
int ele=Integer.parseInt(in.readLine());
p=new node(ele);
if(start==null)
start=p;
else
{
q=start;
while(q.next!=null)
q=q.next;
q.next=p;
}
}
}
public void insertBeg(int ele)
{
node z= new node(ele);
z.next=start;
start=z;
}
public void insertEnd(int ele)
{
node z=new node(ele);
if(start==z);
else
{
node q=start;
while(q.next!=null)
q=q.next;
q.next=z;
}
}
public void insertPos(int ele,int pos)
{
node z=new node (ele);
node q=start;
for(int i=0;i<pos-2;i++)
{
q=q.next;
z.next=q.next;
q.next=z;
}
}
public int deleteBeg()
{
node p=start;
start=start.next;
return p.data;
}
public int deleteEnd()
{
node p,q=start;
if(start.next==null)
{
p=start;
start=null;
}
else
{
while(q.next.next!=null)
q=q.next;
p=q.next;
q.next=null;
}
return p.data;
}
public int deletePos(int pos)
{
node p=null,q=start;
for(int i=0;i<pos-2;i++)
{q=q.next;
p=q.next;
q.next=p.next;}
return p.data;
}
public void display()
{
node q=start;
for(int i=0;q.next!=null;i++)
{
System.out.print(q.data+" ");
q=q.next;
}
System.out.println();
}
}
class StackLink
{
public static void main(String args[])throws Exception
{
int ch,pos,pele;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("enter the number of elements to be created");
int n=Integer.parseInt(br.readLine());
LinkedList obj=new LinkedList();
obj.create(n);
while(true)
{
System.out.println("1>.insertBeg");
System.out.println("2>.insertEnd");
System.out.println("3>.insertPos");
System.out.println("4>.DeleteBeg");
System.out.println("5>.Deleteend");
System.out.println("6>.Deletepos");
System.out.println("7>.display");
System.out.println("8>.exit");
ch=Integer.parseInt(br.readLine());
if(ch==8)
{System.out.println("thank you...coded by TG");
break;
}switch(ch)
{
case 1:
System.out.println("enter the element to be inserted in begining");
int ele=Integer.parseInt(br.readLine());
obj.insertBeg(ele);
break;
case 2:
System.out.println("enter the element to be inserted in end");
ele=Integer.parseInt(br.readLine());
obj.insertEnd(ele);
break;
case 3:
System.out.println("enter the element to be inserted in pos");
ele=Integer.parseInt(br.readLine());

System.out.println("enter position inserted");
int pos1=Integer.parseInt(br.readLine());
obj.insertPos(ele,pos1);
break;
case 4:
if(obj.empty())
System.out.println("LINKEDLIST IS EMPTY");
System.out.println("deleted element is"+obj.deleteBeg());
break;

case 5:
if(obj.empty())
System.out.println("LINKEDLIST IS EMPTY");
System.out.println("deleted element is"+obj.deleteEnd());
break;


case 6:
if(obj.empty())
System.out.println("LINKEDLIST IS EMPTY");
System.out.println("enter the pos to be deleted");
pos=Integer.parseInt(br.readLine());

System.out.println("deleted element is"+obj.deletePos(pos));
break;

case 7:
if(obj.empty())
System.out.println("LINKEDLIST IS EMPTY");
obj.display();
break;
}
}
}
}
/*
OUTPUT:
enter the number of elements to be created
3
Enter the DAta::=
21
Enter the DAta::=
12
Enter the DAta::=
32
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
1
enter the element to be inserted in begining
1
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
2
enter the element to be inserted in end
7
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
3
enter the element to be inserted in pos
24
enter position inserted
2
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
7
1       21      12      32
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
4
deleted element is1
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
5
deleted element is7
1>.insertBeg
2>.insertEnd
3>.insertPos
4>.DeleteBeg
5>.Deleteend
6>.Deletepos
7>.display
8>.exit
8
thank you...coded by TG
*/