/*This is just an annotated version of something that came up
 *during 'consultation time'.
 *It's to help illustrate the notion of an 'array of arrays'.
 *Note that it's a bit on the tricky side, so it's okay if it
 *seems a bit wonky.
 */
public class Puzzle {
	public Puzzle() {
		/*We can hard-code multidimensional arrays, but I wouldn't say it's
		 * common for values.
		 * A more common use case might be, say, for labels
		 * (i.e. several sets of Strings)
		 *In this case, the array is:
		 *    1 2 3 4
		 *    7
		 *    9 5
		*/
		int[][] arr={{1,2,3,4}, {7}, {9,5}};
		System.out.println("Before:");
		display(arr);
		System.out.println("\n");
		
		//This looks vaguely like it's rotating the rows, but is it?
		for (int i=1; i<arr.length;i++)
			arr[i-1]=arr[i];
		arr[arr.length-1]=arr[0];
		/*Btw, notice that we're only using a single [subscript] for these.
		 *That's because we aren't using the individual values, but rather
		 * the rows themselves.
		*/
		
		//I would suggest trying to predict the output before running:
		System.out.println("After:");
		display(arr);
		
		/*This part is commented-out because it might not be immediately
		 * obvious exactly what's going on up to this point.
		 *Once you've run it as-is, try to predict what this change will do.
		 * (And then uncomment-this, recompile, and see)
		*/
		//arr[0][0]=6;
		//display(arr);
		
		///////////////
		//This is just a separate example
		/*
		int[] oneDee={1,3,5,7,9};
		displayRow(oneDee);
		displayRow(arr[1]);
		*/
	}
	
	private void displayRow(int[] row) {
		for (int value:row)
			System.out.print(" "+value);
		System.out.println();
	}
	
	private void display(int[][] arr) {
		for (int[] row:arr) {
			for (int value:row)
				System.out.print(" "+value);
			System.out.println();
		}
	}
	
	public static void main(String[] args) {
		new Puzzle();
	}
}