Kropki Sudoku
Place a digit from 1 to 9 into each of the empty squares so that each digit appears exactly once in each of the rows, columns and the nine outlined 3x3 regions.If absolute difference between two digits in neighbouring cells equals 1, then they are separated by a white dot. If the digit is a half of digit in the neighbouring cell, then they are separated by black dot. The dot between 1 and 2 can be either white or black.
Sudokus that no one can solve
Sudokus that no one can solve, not only including Sodukus which is very difficult but also that no one trying to solve it.