/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package linkedlist;

import java.util.LinkedList;

/**
 *
 * @author chloe
 */
public class MyList<E> {

    private Node<E> head;

    class Node<E> {

        E e; // Data than can be anything
        Node<E> link; // Address of another node

    }

    public boolean add(E e)
    {
        Node<E> newNode = new Node<E>();
        newNode.e = e;
        
        if (head == null) {
            head = newNode;
        } else {
            Node<E> p = head;
            Node<E> pTrail = head;
            while (p != null) {
                pTrail = p;
                p = p.link;
            }
            pTrail.link = newNode;
        }
        return true;
    }
    
 public boolean add(E e, int index) {
        Node<E> newNode = new Node<E>();
        newNode.e = e;//copy data

        //Check index location
        if (index < 0 || index > size()) {
            throw new IndexOutOfBoundsException();
        }

        //Case 1: list is empty and the index is zero
        if (size() == 0 && index == 0) {
            head = newNode;
        } //Case 2: Add at front
        else if (index == 0) {
            //Connect newNode with the first node
            newNode.link = head;
            //Make head point to new node
            head = newNode;
        }
        //Case 3: Add in middle
        else if (index < size())
        {
            Node<E> p = head;
            for (int i = 0; i < index - 1; ++i)
            {
                p = p.link;//advance the p
            }
            //Point link of new node to next node
            newNode.link = p.link;
            //make previous node link point to new node
            p.link = newNode;
        }
        //Case 4: Add at end of list
        else {
            add(e);
        }
        return true;
    }

    @Override
    public String toString()
    {
        String s = "";
        Node<E> p = head;
        while (p != null) {
            s += p.e.toString() + " ";
            p = p.link;
        }
        return "MyList{" + s + "}";
    }
    
        public int size()
    {
        int count = 0;
        Node<E> p = head;
        while (p != null) {
            ++count;
            p = p.link;
        }
        return count;
    }
        
        public E removeAt(int index) {
            if (size() == 0) {
                throw new EmptyListException("The list is empty.");
            }
            if (index < 0 || index >= size())
                throw new IndexOutOfBoundsException();
            if (size() == 0) 
                throw new EmptyListException("Empty List");
            E removedE = null;
            if (index == 0) {
                // remove the front
                removedE = head.e;
                Node<E> p  = head;
                head = head.link;
                p.link = null;
            }
            if (index > 0 && index < size()) { // remove middle
                Node<E> p = head;
                for (int i = 0; i < index - 1; ++i) {
                    p = head.link;
                }
                removedE = p.link.e;
                p.link = p.link.link;
            } else { // Remove at end
                Node<E> p = head;
                for (int i = 0; i < index -1; ++i) {
                    p = p.link;
                    removedE = p.link.e;
                    p.link = null;
                }
            }
            return removedE;
        }

    public static void main(String[] args)
    {
        LinkedList<Integer> linkedList = new LinkedList<>();
        MyList<Integer> ml = new MyList<>();
        ml.add(10);
        ml.add(20);
        ml.add(30);
        ml.add(5, 0);
        ml.add(25, 3);
        ml.add(40, 5);
        System.out.println("removing " + ml.removeAt(2) + "...");
        System.out.println(ml);
        System.out.println(ml.size());
    }
}