// CSE 143, Winter 2009, Marty Stepp
// An ArrayIntList object stores an ordered list of integers using
// an unfilled array.
// This version of the class adds new methods: remove, indexOf, toString.
// It also adds a second constructor with a capacity parameter.
//
// Please DO NOT use this version of the file for your homework assignment.
// Use the one located on the Homework section of the course web site.

public class ArrayIntList {
    // data (fields)
    // They are 'protected' to allow subclasses to access them.

    protected int[] elementData;   // stores the list's elements
    protected int size;            // number of elements in the list
    

    // constructors (creates/initializes new objects)
    
    // Initializes a new empty list that can hold up to 1000 integers.
    public ArrayIntList() {
        this(1000);
    }
    
    // Initializes a new empty list that can hold up to the given number of integers.
    public ArrayIntList(int capacity) {
        elementData = new int[capacity];
        size = 0;
    }

    
    // behavior (methods)

    // Adds the given value to the end of the list.
    // Precondition: size < elementData.length
    public void add(int value) {
        elementData[size] = value;
        size++;
    }
    
    // Inserts the given value into the list at the given index,
    // sliding subsequent elements right to make room for it.
    // Precondition: size < elementData.length and 0 <= index <= size
    public void add(int index, int value) {
        // shift elements right to make room for the new element
        for (int i = size; i > index; i--) {
            elementData[i] = elementData[i - 1];
        }
        elementData[index] = value;
        size++;
    }
    
    // Returns the value in the list at the given index.
    // Precondition: 0 <= index < size
    public int get(int index) {
        return elementData[index];
    }
    
    // Sets the given index to store the given value.
    // Precondition: 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;
    }
    
    
    // Removes the element from the given index from this list,
    // sliding subsequent elements left to fill the gap created.
    // Precondition: 0 <= index < size
    public void remove(int index) {
        for (int i = index; i < size - 1; i++) {
            elementData[i] = elementData[i + 1];
        }
        size--;
        elementData[size] = 0;   // optional
    }
    
    // Returns the first index at which the given value is found in this list.
    // If the value is not found, returns -1.
    public int indexOf(int value) {
        for (int i = 0; i < size; i++) {
            if (elementData[i] == value) {
                return i;
            }
        }
        
        return -1;  // not found
    }
    
    // Returns a String representation of this list, such as "[10, -3, 42, 9]".
    public String toString() {
        if (size == 0) {
            return "[]";
        } else {
            // fencepost problem
            String result = "[" + elementData[0];
            for (int i = 1; i < size; i++) {
                result += ", " + elementData[i];
            }
            result += "]";
            return result;
        }
    }
}