From the Free Press: Sudoku is a number-placing puzzle based on a 9x9 grid with several given numbers. The object is to place the numbers 1 to 9 in the empty squares so that each row, each column and each 3x3 box contains the same number only once.
In this assignment you are to write a Sudoku Checker Program that reads in values from a file and initializes a 2-dimensional (9x9) array with those values. The code for reading the file values into an array is available on D2L. You may and should incorporate this code into your submission. You will, of course, have to modify this code.
Your program must include implementations of the following static methods:
public static boolean rowsAreValid(int[][] array)
public static boolean columnsAreValid(int[][] array)
public static boolean regionsAreValid(int[][] array)
public static boolean puzzleIsValid(int[][] array)
You may and should implement other helper methods. Hint: A rowIsValid() method would, e.g., be perfectly in order.
Note that when you implement these methods, you may NOT use any arithmetic on the values in a row, column or region! E.g., the sum of the values in a row, column or region of a valid sudoku puzzle is 45. You are NOT allowed to simply sup up the values in a row, column or region and check if that sum is 45.