SOURCE CODE: import java.util.Iterator; public class CircularLinkedList implements Iterable { Node head , tail; int size; CircularLinkedList() { head = null; tail = null; size = 0; } public boolean add(E e) { Node ele = new Node(e); ele.next = head; if(head == null) { head = ele; ele.next = head; tail = head; } else { tail.next = ele; tail = ele; } size++; return true; } public boolean add(int index, E e){ Node ele = new Node(e); Node ptr = head; index = index - 1 ; for (int i = 1; i < size - 1; i++) { if (i == index) { Node tmp = ptr.next; ptr.next = ele; ele.next = tmp; break; } ptr = ptr.next; } size++ ; return true; } private Node getNode(int index ) { return null; } public E remove(int index) { Node ret; if (size == 1 && index == 1) { ret = head; head = null; tail = null; size = 0; return ret.getElement(); } if (index == 1) { ret = head; head = head.next; tail.next = head; size--; return ret.getElement(); } if (index == size) { Node s = head; Node t = head; while (s != tail) { t = s; s = s.next; } ret = tail; tail = head; tail = t; size --; return ret.getElement(); } Node ptr = head; index = index - 1 ; for (int i = 1; i < size - 1; i++) { if (i == index) { Node tmp = ptr.next; tmp = tmp.next; ptr.next = tmp; break; } ptr = ptr.next; } size-- ; return ptr.getElement(); } public String toString() { Node current = head; String result = \"\"; if(size == 0){ return \"\"; } if(size == 1) { return head.getElement().toString(); } else{ do{ result = result + current.getElement().toString(); result = result + \" ==> \"; current = current.next; } while(current != head); } return result; } public Iterator iterator() { return new ListIterator(); } private class ListIterator implements Iterator{ Node nextItem; Node prev; int index; @SuppressWarnings(\"unchecked\") public ListIterator(){ nextItem = (Node) head; index = 0; } public boolean hasNext() { return size != 0; } public E next() { prev = nextItem; nextItem = nextItem.next; index = (index + 1) % size; return prev.getElement(); } public void remove() { int target; if(nextItem == head) { target = size - 1; } else{ target = index - 1; index--; } CircularLinkedList.this.remove(target); //calls the above class } } // Solve the problem in the main method // The answer of n = 13, k = 2 is // the 11th person in the ring (index 10) public static void main(String[] args){ CircularLinkedList l = new CircularLinkedList(); int n=13; int k=2; for(int i=1;i<=n;i++) l.add(Integer.valueOf(i)); int j = 13,i=0; while(j>0) { System.out.println(l.toString()); i = i + k; if(i>j) i = k; l.remove(i); j--; } } } OUTPUT: 1 ==> 2 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==> 1 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==> 1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==> 1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==> 1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==> 1 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==> 1 ==> 4.

1. SOURCE CODE:
import java.util.Iterator;
public class CircularLinkedList implements Iterable {
Node head , tail;
int size;
CircularLinkedList() {
head = null;
tail = null;
size = 0;
}
public boolean add(E e) {
Node ele = new Node(e);
ele.next = head;
if(head == null)
{
head = ele;
ele.next = head;
tail = head;
}
else
{
tail.next = ele;
tail = ele;
}
size++;
return true;
}
public boolean add(int index, E e){
Node ele = new Node(e);
Node ptr = head;
index = index - 1 ;

2. for (int i = 1; i < size - 1; i++)
{
if (i == index)
{
Node tmp = ptr.next;
ptr.next = ele;
ele.next = tmp;
break;
}
ptr = ptr.next;
}
size++ ;
return true;
}
private Node getNode(int index ) {
return null;
}
public E remove(int index) {
Node ret;
if (size == 1 && index == 1)
{
ret = head;
head = null;
tail = null;
size = 0;
return ret.getElement();
}
if (index == 1)
{
ret = head;
head = head.next;
tail.next = head;
size--;
return ret.getElement();
}

3. if (index == size)
{
Node s = head;
Node t = head;
while (s != tail)
{
t = s;
s = s.next;
}
ret = tail;
tail = head;
tail = t;
size --;
return ret.getElement();
}
Node ptr = head;
index = index - 1 ;
for (int i = 1; i < size - 1; i++)
{
if (i == index)
{
Node tmp = ptr.next;
tmp = tmp.next;
ptr.next = tmp;
break;
}
ptr = ptr.next;
}
size-- ;
return ptr.getElement();
}
public String toString()
{
Node current = head;
String result = "";
if(size == 0){

4. return "";
}
if(size == 1) {
return head.getElement().toString();
}
else{
do{
result = result + current.getElement().toString();
result = result + " ==> ";
current = current.next;
} while(current != head);
}
return result;
}
public Iterator iterator() {
return new ListIterator();
}
private class ListIterator implements Iterator{
Node nextItem;
Node prev;
int index;
@SuppressWarnings("unchecked")
public ListIterator(){
nextItem = (Node) head;
index = 0;
}
public boolean hasNext() {
return size != 0;
}

5. public E next() {
prev = nextItem;
nextItem = nextItem.next;
index = (index + 1) % size;
return prev.getElement();
}
public void remove() {
int target;
if(nextItem == head) {
target = size - 1;
} else{
target = index - 1;
index--;
}
CircularLinkedList.this.remove(target); //calls the above class
}
}
// Solve the problem in the main method
// The answer of n = 13, k = 2 is
// the 11th person in the ring (index 10)
public static void main(String[] args){
CircularLinkedList l = new CircularLinkedList();
int n=13;
int k=2;
for(int i=1;i<=n;i++)
l.add(Integer.valueOf(i));
int j = 13,i=0;
while(j>0)
{
System.out.println(l.toString());

6. i = i + k;
if(i>j)
i = k;
l.remove(i);
j--;
}
}
}
OUTPUT:
1 ==> 2 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 9 ==> 10 ==> 13 ==>
1 ==> 6 ==> 9 ==> 10 ==> 13 ==>
1 ==> 6 ==> 9 ==> 13 ==>
1 ==> 9 ==> 13 ==>
1 ==> 13 ==>
1
Solution
SOURCE CODE:
import java.util.Iterator;
public class CircularLinkedList implements Iterable {
Node head , tail;
int size;
CircularLinkedList() {
head = null;
tail = null;

7. size = 0;
}
public boolean add(E e) {
Node ele = new Node(e);
ele.next = head;
if(head == null)
{
head = ele;
ele.next = head;
tail = head;
}
else
{
tail.next = ele;
tail = ele;
}
size++;
return true;
}
public boolean add(int index, E e){
Node ele = new Node(e);
Node ptr = head;
index = index - 1 ;
for (int i = 1; i < size - 1; i++)
{
if (i == index)
{
Node tmp = ptr.next;
ptr.next = ele;
ele.next = tmp;
break;
}
ptr = ptr.next;
}

8. size++ ;
return true;
}
private Node getNode(int index ) {
return null;
}
public E remove(int index) {
Node ret;
if (size == 1 && index == 1)
{
ret = head;
head = null;
tail = null;
size = 0;
return ret.getElement();
}
if (index == 1)
{
ret = head;
head = head.next;
tail.next = head;
size--;
return ret.getElement();
}
if (index == size)
{
Node s = head;
Node t = head;
while (s != tail)
{
t = s;
s = s.next;
}
ret = tail;
tail = head;

9. tail = t;
size --;
return ret.getElement();
}
Node ptr = head;
index = index - 1 ;
for (int i = 1; i < size - 1; i++)
{
if (i == index)
{
Node tmp = ptr.next;
tmp = tmp.next;
ptr.next = tmp;
break;
}
ptr = ptr.next;
}
size-- ;
return ptr.getElement();
}
public String toString()
{
Node current = head;
String result = "";
if(size == 0){
return "";
}
if(size == 1) {
return head.getElement().toString();
}
else{
do{
result = result + current.getElement().toString();
result = result + " ==> ";
current = current.next;

10. } while(current != head);
}
return result;
}
public Iterator iterator() {
return new ListIterator();
}
private class ListIterator implements Iterator{
Node nextItem;
Node prev;
int index;
@SuppressWarnings("unchecked")
public ListIterator(){
nextItem = (Node) head;
index = 0;
}
public boolean hasNext() {
return size != 0;
}
public E next() {
prev = nextItem;
nextItem = nextItem.next;
index = (index + 1) % size;
return prev.getElement();
}
public void remove() {
int target;

11. if(nextItem == head) {
target = size - 1;
} else{
target = index - 1;
index--;
}
CircularLinkedList.this.remove(target); //calls the above class
}
}
// Solve the problem in the main method
// The answer of n = 13, k = 2 is
// the 11th person in the ring (index 10)
public static void main(String[] args){
CircularLinkedList l = new CircularLinkedList();
int n=13;
int k=2;
for(int i=1;i<=n;i++)
l.add(Integer.valueOf(i));
int j = 13,i=0;
while(j>0)
{
System.out.println(l.toString());
i = i + k;
if(i>j)
i = k;
l.remove(i);
j--;
}
}
}
OUTPUT:
1 ==> 2 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>

12. 1 ==> 3 ==> 4 ==> 5 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 8 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 11 ==> 12 ==> 13 ==>
1 ==> 3 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 7 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 9 ==> 10 ==> 12 ==> 13 ==>
1 ==> 4 ==> 6 ==> 9 ==> 10 ==> 13 ==>
1 ==> 6 ==> 9 ==> 10 ==> 13 ==>
1 ==> 6 ==> 9 ==> 13 ==>
1 ==> 9 ==> 13 ==>
1 ==> 13 ==>
1