Question

I did this sort function in C++ for Linked List

void sort()
{
    node* ctr;
    node* innerctr;
    info temp;
    node* max;
    ctr = start;
    while(ctr!=NULL)
    {
        innerctr=ctr->next;
        max=ctr;
            while(innerctr!=NULL)
            {

                if((innerctr->student.name) > (max->student.name))
                {
                    max=innerctr;

                }


                innerctr=innerctr->next;


            }

            //swapping...


        ctr=ctr->next;
    }
}

I need to do something similar in Java and I want to use the LinkedList ready class but I am a bit confused because there are no pointers.

Answer 1

With as few modifications as possible, nearly the same thing in Java:

class Student {String name = "Joe Doe";}
class Node {
    Node next;
    Student student;
}
class Info {}
public class NodeSorter {

    Node start; 

    void sort()
    {
        Node ctr;
        Node innerctr;
        Info temp;
        Node max;
        ctr = start;

        while (ctr != null)
        {
            innerctr = ctr.next;
            max=ctr;

            while (innerctr != null)
            {
                if ((innerctr.student.name).compareTo (max.student.name) > 0)
                {
                    max = innerctr;
                }
                innerctr=innerctr.next;
            }
            //swapping...
            ctr = ctr.next;
        }
    }
}

• some dummy classes (Student, Info)
• Node would normally be generic, not fixed to Student.
• classnames with Capitals.
• methods and attributes are just delimited with dot
• comparision with compareTo (for non-numbers)

And here is the improved version, with Type “Student” as parameter for the Node:

class Student implements Comparable <Student> {
    String name = "Joe Doe";
    public int compareTo (Student other) {
        if (other == null) return 1;
        return name.compareTo (other.name);
    }   
}
class Node <T> {
    Node <T> next;
    T value;
}
class Info {}
public class NodeSorter {

    Node <Comparable> start;    

    void sort ()
    {
        Node <Comparable> ctr;
        Node <Comparable> innerctr;
        Info temp;
        Node <Comparable> max;
        ctr = start;

        while (ctr != null)
        {
            innerctr = ctr.next;
            max=ctr;

            while (innerctr != null)
            {
                if ((innerctr.value).compareTo (max.value) > 0)
                {
                    max = innerctr;
                }
                innerctr=innerctr.next;
            }
            //swapping...
            ctr = ctr.next;
        }
    }
}

The problem with the unspecified ‘start’ is inherited from you.