Question

Based on the above coordinates in the above image, I’d like to be able to calculate which “square” as highlighted in red, the selected cell belongs to.

I’m solving a sudoku puzzle, and I have access to the width of each square, as well as the row/column at which the cell are located.

I’m having trouble calculating the “number” of the square that the cell belongs to (they start at 1, and increase from left-to-right, top-to-bottom), so that the numbers of the squares above are:

1|2
3|4

How could I go about calculating this? Any suggestions would be appreciated. Either a Java-specific method, or just an algorithm would be fine 🙂

Answer 1

int numMajorRows = 2;
int numMajorCols = 2;  
int width = 2;

// assuming row and col also start at 1.  
int squareNumber(int row, int col) {
  int majorRow = (row-1) / width;  // zero based majorRow
  int majorCol = (col-1) / width;  // zero based majorCol
  return majorCol + majorRow * numMajorCols + 1;
}