java - Dividing a 2D array into boxes -

i having trouble dividing 2d array boxes, in sudoku. have array of squares in board object, , want divide them 2x3 or 3x3 boxes, box objects have 1d array keep track of squares.

k box number, in 9x9 sudoku, boxes numbered 0 through 8.

int l = 0; for(int i=k*a; i<k*a+a;i++){         for(int j=k*b;j<k*b+b;j++){             narray[l]=brd.getsquare(i,j);             brd.getsquare(i,j).setbox(this);             l++;     } 

this gets first box right, goes off after that. i've been thinking hours now, , can't seem wrap head around it. have neat trick this?

so, i'll assume boxes numbered this:

012 345 678 

(and boxes consist of 3x3 cells each)

if i , j x , y coordinates, you'll need translate above coordinates. like:

  0 1 2 3 4 5 6 7 8  x 0 1 2 0 1 2 0 1 2 y 0 0 0 1 1 1 2 2 2 

so x = k%3 , y = k/3.

in actual grid x , y has start 0, 3 , 6 rather 0, 1 , 2, multiply 3.

so should it: (changes depending on coordinate x , y)

int size = 3; int l = 0; for(int = 0; < size; i++){     for(int j = 0; j < size; j++){         int x = + k % size * size;         int y = j + k / size * size;         narray[l] = brd.getsquare(x, y);         brd.getsquare(x, y).setbox(this);         l++;     } }