The SinglyLinkedList code

 

package HW4_Skeleton;

public class SinglyLinkedList {

   private SinglyLinkedNode head;
   private int size;

   public SinglyLinkedList(){
       this.head = null;
       this.size = 0;
   }

   // add a new node at the beginning of the list
   public void addAtBeginning(int value){
       SinglyLinkedNode newNode = new SinglyLinkedNode(value);

       newNode.setNextNode(this.head);
       this.head=newNode;

       this.size++;
   }

   public void reverse() {

   }

 

 

   public SinglyLinkedNode getHead() { return this.head; }

   public int getSize() {
       return this.size;
   }

   @Override
   public String toString(){
       String str = "";
       SinglyLinkedNode curr = this.head;
       while(curr != null){
           str += "->" + curr.getData();
           curr = curr.getNextNode();
       }
       return str;
   }

}

 

The SinglyLinkedListStarter

 

package HW4_Skeleton;

public class SinglyLinkedListStarter {

 

   public static void main(String args[]) {
       
       SinglyLinkedList myLinkedList = new SinglyLinkedList();

       myLinkedList.addAtBeginning(4);
       myLinkedList.addAtBeginning(7);
       myLinkedList.addAtBeginning(1);
       myLinkedList.addAtBeginning(2);

       System.out.println(myLinkedList.toString());
       System.out.println(myLinkedList.getSize());
       System.out.println(myLinkedList.getHead());

       myLinkedList.reverse();

       System.out.println(myLinkedList.toString());
       System.out.println(myLinkedList.getSize());
       System.out.println(myLinkedList.getHead());

   }
}
 

The SinglyLinkedNode

 

package HW4_Skeleton;

public class SinglyLinkedNode {
   private int item;
   private SinglyLinkedNode next;

   public SinglyLinkedNode(int data, SinglyLinkedNode nextNode) {
       this.item = data;
       this.next = nextNode;
   }

   public SinglyLinkedNode(int data) {
       this(data, null);
   }

   public int getData() {
       return item;
   }

   public SinglyLinkedNode getNextNode() {
       return next;
   }

   public void setData(int data) {
       this.item = data;
   }

   public void setNextNode(SinglyLinkedNode nextNode) {
       this.next = nextNode;
   }

   @Override
   public String toString() {
       return ""+this.item;
   }

}

(2) (25 points) In the downloaded skeleton code archive, you find the classes SinglyLinkedNode, SinglyLinkedList, and SinglyLinkedListStarter. This time, you are working with a singly linked list. However, it is not double-ended. Each node in this list in contrast to the previous task only maintains the location of the next node and not the previ- ous one. Also, the list maintains a pointer to the head node only. It does not provide a tail pointer. You can test your code using the class SinglyLinkedListStarter. In this problem, you will write the method reverse () in the class SinglyLinkedList that reverses a singly linked list. Your algorithm must have a worst-case runtime of O(n) and a worst-case space complexity of O(1) beyond the input. For example, if the list contains the integers 5 7 1 2 3 in this order (the head pointer refers to the node containing the item value 5) then the reversed list will look like: 32175 (the head pointer now refers to the node containing the item value 3). That means that you need to modify