Dots and Dots of Threes
- XV and number dots
- Negative constraint
The brief
Standard sudoku rules apply: each row, column, and 3x3 box must contain all the digits from 1 to 9.
Digits in cells separated by a white dot have a difference of 3.
Digits in cells separated by a black dot are in a 1:3 ratio.
All possible black dots are given. It is not necessarily the case that all possible white dots are given.