将元素插入已排序的链表中

Question

I am creating a function that inserts an element into a linked list in the correct order without resorting the list. Here's the code I have:

public void insert(E e) {
    if (e == null)
        throw new NullPointerException();

    if (head == null) {
        head = new Node(e, null);
        count++;
    } else {
        Node current = head;

        for (current = head; current != null ;){
            if(current.item.compareTo(e) > 0){
                Node temp = current;
                current = new Node(e, null);
                current.next = temp;
                break;
            }else{
                current = current.next;
            }
        }
    }   
}

I'm not sure whats going wrong but when I print it out, it only prints out the first element. Am I somehow not linking to the head node? I want it so if it looks through the list and once it finds the item larger then it, it takes that spot and the larger item gets bumped to next. The linked list constructors have already been created outside the list.

Answer 1

When you insert a new element into your list, at no point the next reference of the previous element is set:

if(current.item.compareTo(e) > 0){
    Node temp = current;
    current = new Node(e, null);
    current.next = temp;
    break;
}else
    \\...

As a consequence, next of the first list element will always point to null , effectively leaving the list empty except for the first element.

---

You also never even try to insert the element if the list is not empty and this condition is false for each list element:

if(current.item.compareTo(e) > 0){