Hi,

evert!

Last week I had possibility to solve your puzzles posted by you on November, 27. I enjoy your zerodoku puzzles, but unfortunately I have spare time to solve them on vacations only (going by train). I managed to solve both 10x10 puzzles and both 11x11 puzzles. Thank you for interesting game! I think you can be interested in my rating of these puzzles, so I post my opinion below.

- Code: Select all
`10x10 zerodoku number 1`

6| | | | | | |2|1|

| |1|4| |2| |1| |

|8|0| |0|4| |6| |2

|9| | |0| | | | |0

|7|6| | | | | | |6

9| | |8| |6| | | |0

| |8|9|5|0|1| |5|4

| | | |7| |6| | |3

7| |6| | | |4|5|3|

5|0| | | |2|0| |2|

I think, this is moderate difficulty puzzle. I spent 2.5 hours to solve it.

- Code: Select all
`10x10 zerodoku number 2`

| |9| | | |0|3| |5

|7| | | | | | |0|0

0| | |9| |7| | | |

7| |7|6| |5| | |3|6

| |5| |2| | | | |7

6| | | |5|9|0|4| |0

|7|0| | | |3|6| |

0| | |2| |6|5|8| |

| |9|0| | | | | |

6| |8|3|2|7| |5|6|

I think, this is difficult puzzle, but not tough, because it can be solved by basic techniques only. I spent 3 hours to solve it. This puzzle is one of my favorite zerodoku puzzles.

- Code: Select all
`11x11 zerodoku number 1`

5|7| |8| |5| |0|2| |

2| |0|6| | |3|5|1| |

|7| |9| |0| | | |5|

| | | | |7| | | | |4

|3| | | | |6| | | |

| | |0| | |9| | | |

7|6| | | | | |3|8| |6

8| | |2| |7| | | | |4

| | | |3|5| |7|0| |0

6| | |5|4|9|7|2| | |

| |1| |8|4|2|6| |8|7

I think, this is moderate difficulty puzzle. I spent 2-2.5 hours to solve it.

- Code: Select all
`11x11 zerodoku number 2`

5| | | | |1|4|9|5| |

1| |7|8|9| |2| |6| |3

|4| | | |5|9|3| |7|0

| | |7| | | |8| | |

| | |5| | | |7|9| |

| |4| |7| | |5| | |

|7| |5|8|1| | | | |

0| | | | | | | | | |

| |7|8|9| | | | | |0

3|1| | | |2| |5|0|0|9

0|6|2| | | | | |9|6|

This is very difficult puzzle for me, but not tough, because it can be solved by basic techniques only. I spent a day to solve it. (I was forced 3 times to start from scratch because of my errors in solving process.) I think this puzzle is champion zerodoku puzzle. Well composed puzzle!

Can you compose zerodoku puzzle without zeroes in initial configuration? It could be curious if a 9x9 zerodoku puzzle could exist that can be treated as sudoku puzzle and zerodoku puzzle at the same time.

One observation. Zerodoku has its own unavoidable sets, the smallest possible UA contains 2 cells only.

Thank you for your work!

Serg