Select three methods in the ObjectList class to work through

Select three methods in the ObjectList class to work through algorithmically. Describe any special cases or boundary conditions that might exist for each of the three methods selected. Be sure to draw pictures as you work through the methods. Remember that you cannot work on linked lists without drawing pictures. The homework will not be accepted without submitting the pictures! Write a Java method with the signature: public objectList intersect (objectList list1, objectList list2) that accepts two unordered linear linked lists and returns a third linear linked list whose nodes contains the intersection of the two original linear linked lists. Note that the intersection of two lists is a new list containing the elements that the two lists have in common, without modifying the two original lists. Describe any boundary conditions that might exist.

Solution

Node.java

//Defines each node of a linked list

public class Node{
    int data;
    Node next;
    Node(int d)
    {
        data = d;
        next = null;
    }
}

ObjectList.java

public class ObjectList{
    public Node head;

    /* Utility function to print list */
    public void printList()
    {
        Node temp = head;
        while(temp != null)
        {
            System.out.print(temp.data+\" \");
            temp = temp.next;
        }
        System.out.println();
    }

    /* Inserts a node at start of linked list */
    public void push(int new_data)
    {
        /* 1 & 2: Allocate the Node &
                  Put in the data*/
        Node new_node = new Node(new_data);

        /* 3. Make next of new Node as head */
        new_node.next = head;

        /* 4. Move the head to point to new Node */
        head = new_node;
    }

    /* A utilty function that returns true if data is present
       in linked list else return false */
    public boolean isPresent (int data){
        Node t = this.head;
        while (t != null)
        {
            if (t.data == data)
                return true;
            t = t.next;
        }
        return false;
    }
}

Intersection.java

//Implements the intersection method.

class Intersection{

    static public ObjectList intersect(ObjectList list1, ObjectList list2){
        ObjectList result = new ObjectList();
        //Node t1 = head1;
        Node t1 = list1.head;
        Node t2 = list2.head;
        // Traverse list1 and search each element of it in list2.
        // If the element is present in list 2, then insert the
        // element to result
        while (t1 != null){
            if (list2.isPresent(t1.data))
                result.push(t1.data);
            t1 = t1.next;
        }
        return result;
    }

    /* Driver program to test above functions */
    public static void main(String args[]){

        ObjectList llist1 = new ObjectList();
        ObjectList llist2 = new ObjectList();
        ObjectList unin = new ObjectList();
        ObjectList intersecn = new ObjectList();

        /*create a linked lits 10->15->5->20 */
        llist1.push(20);
        llist1.push(4);
        llist1.push(15);
        llist1.push(10);

        /*create a linked lits 8->4->2->10 */
        llist2.push(10);
        llist2.push(2);
        llist2.push(4);
        llist2.push(8);

        intersecn = intersect(llist1, llist2);
        intersecn.printList();

    }
}