//ArrayStuff.java

import java.util.*;    //for Arrays utility class


public class ArrayStuff {
    public static void main(String[] args) {

	int[] arr;   //declare an array.    
	//int[5] arr; syntax error!

	arr = new int[5];  //construct array (create an array object)
	//array elements automatically initialiized to zero

	arr[2] = 345;  //access element like in C

	//	arr[5] = 34543;  //runtime error.  index out of bounds.

	//combined declare and construct:
	int[] arr2 = new int[5];

	//int[] arr = new int[];   //syntax error

	//size determined at runtime:  using cmd line arg as example:
	int size = Integer.parseInt(args[0]);
	int[] arr3 = new int[size];

	System.out.println("Initialized array: ");
	for (int i=0; i<size; i++)
	    System.out.print(arr3[i] + " ");
	System.out.println();

	do_stuff(arr3);   //array as method argument
	//method changes the array:
	System.out.println("After the method: ");
	for (int i=0; i<size; i++)
	    System.out.print(arr3[i] + " ");
	System.out.println();

    }


    public static void do_stuff(int[] A) {

	//assign random values
	System.out.println("Unsorted array: ");
	for (int i=0; i<A.length; i++) {
	    A[i] = (int)(Math.random() * 100);
	    System.out.print(A[i] + " ");
	}
	System.out.println();

	Arrays.sort(A);    
	System.out.println("Sorted array: ");
	for (int i=0; i<A.length; i++)
	    System.out.print(A[i] + " ");
	System.out.println();
    }
}


/*
change so range of ints is cmd line arg

add Arrays.binarySearch(arr,x)
add read_int 

*/