// CSE 143, Winter 2011, Marty Stepp
// An ArrayIntList object stores an ordered list of integers using
// an unfilled array.
// This is an unfinished "in-progress" version of the class.
// We will work on it more in Tuesday's section and Wednesday's lecture.

import java.util.*;   // for Arrays

public class ArrayIntList {
    private static final int INITIAL_CAPACITY = 10;
    
    // fields - the data inside each ArrayIntList object
    private int size;
    private int[] elementData;
    
    // Initializes a new empty list with initial capacity of 10 integers.
    public ArrayIntList() {
        size = 0;
        elementData = new int[INITIAL_CAPACITY];
    }
    
    // Adds the given value to the end of the list.
    // If necessary, resizes the array to fit the value.
    public void add(int value) {
//      checkResize();
//      elementData[size] = value;
//      size++;

        // just call the other add method (to remove redundancy)
        add(size, value);
    }

    // Inserts the given value into the list at the given index.
    // If necessary, resizes the array to fit the value.
    // For now we will assume that 0 <= index <= size.
    public void add(int index, int value) {
        checkResize();
        
        // slide elements to the right to make room
        for (int i = size; i > index; i--) {
            elementData[i] = elementData[i - 1];
        }
        
        // insert the value in the hole we just made
        elementData[index] = value;
        size++;
    }
    
    // Returns the value in the list at the given index.
    // For now we will assume that 0 <= index < size.
    public int get(int index) {
        return elementData[index];
    }
    
    // Sets the given index to store the given value.
    // For now we will assume that 0 <= index < size.
    public void set(int index, int value) {
        elementData[index] = value;
    }
    
    // Returns the number of elements in the list.
    public int size() {
        return size;
    }
    
    // Returns true if the list does not contain any elements.
    public boolean isEmpty() {
        return size == 0;   // "boolean zen"
    }
    
    // Removes the value from the given index, shifting following elements left
    // by 1 slot to cover the hole.
    // For now we will assume that 0 <= index < size.
    public void remove(int index) {
        for (int i = index; i <= size - 1; i++) {
            elementData[i] = elementData[i + 1];
        }
        size--;
    }
    
    // A "private helper method" to resize the array if necessary.
    // Checks whether the list's array is full, and if so,
    // doubles its size so that more elements can be added.
    private void checkResize() {
        if (size == elementData.length) {
            // resize the array
            elementData = Arrays.copyOf(elementData, 2 * size);
        }
    }
}