// CSE 143, Winter 2009, Marty Stepp
// A LinkedIntList object represents a linked list of integer values.

public class LinkedIntList {
    private ListNode front;   // reference to front node in list (null if empty)
    
    // Constructs a new empty list.
    public LinkedIntList() {
        front = null;
    }
    
    // Adds the given value to the end of the list.
    public void add(int value) {
        if (front == null) {
            // adding to an empty list
            front = new ListNode(value);
        } else {
            // adding to the end of an existing list;
            // traverse to the last node in the list so we can append to it
            ListNode current = front;
            while (current.next != null) {
                current = current.next;
            }
            
            // at this point, current.next == null,
            // and current refers to the last node
            current.next = new ListNode(value);
        }
    }
    
    // Adds the given value at the given index in the list.
    // Precondition: 0 <= index <= size
    public void add(int index, int value) {
        // TODO: implement this
    }
    
    // Removes the element at the given index from the list.
    // Precondition: 0 <= index < size
    public void remove(int index) {
        if (index == 0) {
            // removing the first element must be handled specially
            front = front.next;
        } else {
            // removing some element further down in the list;
            // traverse to the node before the one we want to remove
            ListNode current = front;
            for (int i = 0; i < index - 1; i++) {
                current = current.next;
            }
            
            // change its next pointer to skip past the offending node
            current.next = current.next.next;
        }
    }
    
    // Returns the integer value at the given index in the list.
    // Precondition: 0 <= index < size
    public int get(int index) {
        // traverse to the node at the given index
        ListNode current = front;
        for (int i = 0; i < index; i++) {
            current = current.next;
        }
        return current.data;
    }
}