How to implement circular linked list in java?

Question

I read a book about \"Data structures and algorithms\" in which there is assignment which asks me to implement a circular linked list. This is a learning exercise and my code ma

Answer 1

Add last.next = first before return temp in your delete() function:

public Link delete() {
    if(first.next == null) 
        last = null;
    Link temp = first;
    first = first.next;
    if(last != null)
        last.next = first
    return temp;
} 

Updated:

I cannot find a scenario which satisfy first.next == null, and we should take into consideration calling delete() on an empty list.

public Link delete() {
    Link temp = first;
    if(first == null){
        ;  // or you can throw some exception as a warning
    }
    else if(first==last){  // only one element
        first = null; // reset to initial state
        last = null;
    }
    else{
        first = first.next;
        last.next = first;
    }
    return temp;
}