// Class LinkedIntList can be used to store a list of integers.

public class LinkedIntList implements IntList {
    private ListNode front;  // first value in the list

    // post: constructs an empty list
    public LinkedIntList() {
        front = null;
    }

    // post: appends the given value to the end of the list
    public void add(int value) {
        if (front == null)
            front = new ListNode(value);
        else {
            ListNode current = front;
            while (current.next != null)
                current = current.next;
            current.next = new ListNode(value);
        }
    }
}