Kropki Sudoku - 250 Jigsaw Kropki Sudoku Puzzles (Volume 12)

Kropki Sudoku (the Polish word “kropki” means “dots”; also known as “Dots Sudoku”) is the variation of the original sudoku. If absolute difference between two digits in neighboring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighboring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black. Also the puzzle may contain the regions of random (irregular) shape; this variant is called Jigsaw Sudoku (“Geometry Sudoku”, “Geometry Number Place”, “Irregular Sudoku”, “Kikagaku Nanpure”).