Sunday 27 December 2015

Daily League #53: Quad Division Sudoku

This is the fourth and last Sudoku in the 'Quad Sudoku' series. It's as far as I know a new variant. I wish I could check somewhere what variants have been done already. I though it would be nice to have a variant where the four cells were treated as two two-digit numbers. I considered turning the Diagonal Difference puzzle from instructionless round of the last WPC into a Sudoku, but I had already made a Quad puzzle with differences. Then I figured I could do something similar with division.
I just started playing around with a few placements and I noticed that the clues carry a lot of impact. They give you a lot of information and you get placements pretty quick. So I figured it should be possible to make one without any givens. I always enjoy trying to turn out Sudokus without any givens, which most people doing my Daily League puzzles must have noticed. This puzzle had an opening constructed pretty quickly. The problem of course was to get it unique with only valid clues. I had a few puzzles that were close but I couldn't get any valid clues in anymore to make it unique. After a few tries, this puzzle came out. I don't think it's overly hard, but it does involve a bit of careful calculations to make sure you don't make any errors. There's very little chance to track back.

Rules for Sudoku

In this Sudoku, a number on a grid point indicates the result of dividing the two-digit number formed by the top two digits by the two-digit number formed by the bottom two digits. Both two-digit numbers have to be read from left to right.

Click to enlarge