Rules :
1) Rules of Classic sudoku apply.
2) Place digits 1-9 in each row, each column and each 3*3 region.
3) If the absolute difference between two digits in neighbouring
cells is 1, then a white dot is indicated.
4) If the digit in a cell is half of the digit in a neighbouring cell, then
black dot is indicated.
5) Remember if neighbouring cells are 1 and 2, then they can have
either of the dots black or white.
Example : This example is taken from SUDOKU CUP 2009
1) Rules of Classic sudoku apply.
2) Place digits 1-9 in each row, each column and each 3*3 region.
3) If the absolute difference between two digits in neighbouring
cells is 1, then a white dot is indicated.
4) If the digit in a cell is half of the digit in a neighbouring cell, then
black dot is indicated.
5) Remember if neighbouring cells are 1 and 2, then they can have
either of the dots black or white.
Example : This example is taken from SUDOKU CUP 2009
Solution :