Question

Given the following definition of the LNode class, implement the non-recursive method saveCountinLastNode and the recursive method addOddNodes for the LinkedList class which represents singly linked lists.

public class LNode
{
private int m_info;
private LNode m_link;

public LNode(int info){
m_info = info;
m_link = null;
}
public void setLink(LNode link){
m_link = link;
}
public LNode getLink(){
  return m_link;
}
public void setInfo(int info){
m_info = info;
}
public int getInfo(){
  return m_info;
}
}

public class LinkedList
{
private LNode head; // a reference to the first node
// in the list
public LinkedList()
{
head = null;
}

// This non-recursive method traverses the list and
// count the total number of nodes and then save it
// in the last node. You can assume that the list has
// at least one node.
// You will receive zero points if recursion is used.
// For example, the following linked list on the left
// has 3 nodes, so after this method is executed, the
// list will be updated to the one on the right.

public void saveCountinLastNode()
{
  // TODO: implement this method
}

// This recursive method computes the sum of all the nodes
// with odd values.
// You will receive zero points if any looping statements
// are used.
public int addOddNodes(LNode node)
{
  // TODO: implement this method
}
}

Answer 1

- I have included a main method just for testing. Please remove it.

Kindly upvote if this helped

Sample output




CODE:

class LNode {
    private int m_info;
    private LNode m_link;

    public LNode(int info) {
        m_info = info;
        m_link = null;
    }
    public void setLink(LNode link) {
        m_link = link;
    }
    public LNode getLink() {
        return m_link;
    }
    public void setInfo(int info) {
        m_info = info;
    }
    public int getInfo() {
        return m_info;
    }
}

public class LinkedList {
    static int sum = 0;
    private LNode head; // a reference to the first node
    // in the list
    public LinkedList() {
        head = null;
    }

    // This non-recursive method traverses the list and
    // count the total number of nodes and then save it
    // in the last node. You can assume that the list has
    // at least one node.
    // You will receive zero points if recursion is used.
    // For example, the following linked list on the left
    // has 3 nodes, so after this method is executed, the
    // list will be updated to the one on the right.

    public void saveCountinLastNode() {
        LNode current = head;
        LNode temp;
        int count = 0;
        while (current != null) {
            count++;
            if (current.getLink() == null) {
                LNode newNode = new LNode(count);
                current.setLink(newNode);
                break;
            }
            current = current.getLink();
        }
    }

    // This recursive method computes the sum of all the nodes
    // with odd values.
    // You will receive zero points if any looping statements
    // are used.
    public int addOddNodes(LNode node) {
        if (node != null) {
            if (node.getInfo() % 2 != 0) {
                //it is odd value
                sum += node.getInfo(); // have to take a static variable sum as in recursion it will get initialized to default value if we do not take static
            }
            addOddNodes(node.getLink());
        }
        return sum;
    }

    public void dis() {
        LNode current = head;
        while (current != null) {
            System.out.print(current.getInfo() + " ");
            current = current.getLink();
        }
    }

    public static void main(String[] args) {
        //LNode ll = new LNode(3);
        LinkedList l = new LinkedList();
        l.head = new LNode(3);
        l.saveCountinLastNode();
        l.dis();
        int sum = l.addOddNodes(l.head);
        System.out.println("Sum is " + sum);

    }

}