Write a function to remove a single linked list's nth from last element.

gistfile1.java

    /**
     * Removes the list's nth from last element.
     */
    public void removeNthFromLast(List list, int n) {
        Node ahead = list.head;
        for (int x = 0; x < n; x++) {
            if (ahead.next == null) {
                return null;
            }
            ahead = ahead.next;
        }

        // When deleting the first element take care to not lose the
        // list head.
        if (ahead.next == null) {
            list.head = list.head.next;
            return;
        }

        ahead = ahead.next;
        Node prev = list.head;
        while (ahead.next != null) {
            ahead = ahead.next;
            prev = prev.next;
        }
        prev.next = prev.next.next;
    }