Notes

package explab;

import java.util.*;

public class EXF1_04
{

public static class CLLNode<T> {

public T info;
public CLLNode<T> next;
public CLLNode() {
next = null; }
public CLLNode(T el) {
info = el;
next = null; }
public CLLNode(T el, CLLNode<T> ptr) {
info = el;
next = ptr; }
}

public static class CLL<T>

{
private CLLNode<T> head,tail;

public CLL(){
head=tail=null;
}

public boolean isEmpty(){
return head == null;
}

public void AddTail(T el){
if
(isEmpty())
head = tail = new CLLNode<T>(el, head);
else
{
tail.next = new CLLNode<T>(el, head);
tail = tail.next;
}
}

public T RemoveHead(){
if (isEmpty())
return null;
T el = head.info;
if (head == tail)
head = tail = null;
else
head = head.next;
tail.next =head;
return el;

}


public String print() { // you can use this for toString()
CLLNode<T> p; String s = "";
for (p = head; p != null; p = p.next)
s=s+p.info.toString() + " ";
return s; }

public CLLNode<T> getNode(T el) {
CLLNode<T> p = head;
while (p != null && p.info != el) p = p.next;
return p;
}

public void simulation()
{
CLLNode<T> p1, p2;
p1 = head;
p2 = head;

while(!(isEmpty()))
{
p1 = p1.next.next.next;
p2 = p2.next.next;

System.out.print(p1.info);
p2.next=p1.next;

if(p2!=p2.next)
{p2=p2.next; p1=p2;}
else
head=null;
}

}


}

public static void main(String[] args) {
Scanner scan = new Scanner (System.in);
char x;
char i;
char bool='y';
char sure='y';


CLL<Character> sl = new CLL<Character>();
do{
System.out.println("Main Menu:");
System.out.println("A: Add Node");
System.out.println("B: Trace Simulation");
System.out.println("C: Make null");
System.out.println("D: Exit Program");
System.out.println("Enter letter of Choice: ");

x = scan.next().charAt(0);

if(x=='a'||x=='A')
{
do
{
System.out.println("Enter character to add:");
i=scan.next().charAt(0);
sl.AddTail(i);
System.out.println("Again?(Y/N)");
bool=scan.next().charAt(0);
} while(bool=='y'||bool=='Y');
}

if(x=='b'||x=='B')
{
System.out.print(sl.RemoveHead());
sl.simulation();
System.out.println();
}

if(x=='c'||x=='C')
{
do {
System.out.println("Are you sure? y/n");
sure = scan.next().charAt(0);
if(sure=='y'||sure=='Y')

sl = new CLL<Character>();

}while(bool=='y'||bool=='Y');

}

if(x=='d'||x=='D')
{
System.exit(0);
}




}while (x!='j'||x!='J');

}
}