Insertion Sort for linked list help?

[bubtub24]

Hi, I'm writing an Insertion sort for linked lists and I have the sort working but if I add certain numbers to the list it won't work. I cannot figure out what could be causing this error. It sorts [4, 2, 1, 5, 3, 10, 6, 11, 7] perfectly, but if I add a 9 to the end or other numbers it doesn't work:confused: Any help would be g
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[pbrockway2]

I have the sort working but if I add certain numbers to the list it won't work

It's time to debug!

The thing is to see what it is that your program is doing. IDE's offer debuggers, or you can use the poor man's debugger: System.out.println(). (Actually the latter has some advantage because others here can see your code and run it.)

    /** 
     * Returns the list from first onwards 
     * as a string of info values. 
     */
static String asString() 
{
    StringBuilder buf = new StringBuilder();
    for(Node n = first; n != null; n = n.link) 
    {
        buf.append(n.info).append(" ");
    }
    return buf.toString();
}

// ...

public static <T> void insertSort()
{
    Node<Integer> current, head, trail;

    current = first;
    trail = current;
    head = current.link;

    while(current != null)
    {
        System.out.println("head=" + head.info);
        System.out.println("trail=" + trail.info);
        System.out.println("current=" + current.info);
        if(head.info < trail.info)
        {
            System.out.print("Found " + head.info + " out of order: ");
            int temp = head.info;
            deleteNode(temp);
            position(temp);

        } 
        else 
        {
            System.out.print(head.info + " OK: ");
        }
        System.out.println(asString() + "\n");
        trail = current;
        head = current.link;
        current = current.link;
    }
}

Basically you are looking to see at what point the head, trail, and current values are not what you expect them to be.

[bubtub24]

Thanks for the information it was the trail and head that were wrong. It needed a small amount of tweaking now is fixed.:)

[pbrockway2]

Well done. I'm glad you've got it sorted out.