Flip the Script
- Region sum lines
- Same-class lines
The brief
- Normal sudoku rules apply, i.e. each row, column, and 3x3 region has to contain the digits from 1 to 9 once each.
- Entropy Mirror: We consider the digits from 1 to 9 as three entropic groups: low (1, 2, 3), medium (4, 5, 6) and high digits (7, 8, 9). The diagonal from r1c1 to r9c9 acts as an entropy mirror. Each cell has the same entropy as the cell reflected in the mirror, i.e. if r2c6 contains a low digit, then r6c2 must also have a low digit.
- Region Sum Lines: Box borders divide the blue lines into segments with the same sum. (Different lines may have different sums.)