Timeline for What is the fewest number of clues on a rotationally symmetrical sudoku grid with a unique solution?
Current License: CC BY-SA 3.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 12, 2021 at 7:49 | comment | added | Kruga | en.wikipedia.org/wiki/… | |
| May 11, 2021 at 19:40 | history | edited | bobble |
edited tags
|
|
| Apr 13, 2017 at 12:50 | history | edited | CommunityBot |
replaced http://puzzling.stackexchange.com/ with https://puzzling.stackexchange.com/
|
|
| May 16, 2014 at 16:17 | answer | added | user88 | timeline score: 10 | |
| May 16, 2014 at 15:07 | comment | added | user88 | @Kevin Done and done. | |
| May 16, 2014 at 15:06 | history | edited | user88 | CC BY-SA 3.0 |
added 173 characters in body
|
| May 16, 2014 at 15:05 | comment | added | Kevin | @JoeZ. you should probably clarify that in the question. | |
| May 16, 2014 at 15:04 | comment | added | Kevin | @ratchetfreak I see, you mean the center row, column, and 3x3. Joe and I interpreted your statement as saying the center (5,5) itself was breaking the symmetry. | |
| May 16, 2014 at 15:04 | comment | added | user88 | They don't have to be the same number. The only thing that's rotationally symmetrical is that the square is filled in. | |
| May 16, 2014 at 15:02 | comment | added | ratchet freak | @kevin for example the number at 5,1 must also be at 5,9 (1 based index) this immediately violates the sudoku invariant | |
| May 16, 2014 at 14:59 | comment | added | Kevin | @ratchetfreak why do you think the center can't be symmetric? Like Joe said, it is trivially symmetric. | |
| May 16, 2014 at 14:29 | comment | added | ratchet freak | still the center square can't be 180° rotational symmetrical, and the squares on the sides can't be part of that | |
| May 16, 2014 at 14:15 | comment | added | user88 | By rotationally symmetrical, I mean the positions of the clues can be rotated 180 degrees and will overlap itself perfectly. | |
| May 16, 2014 at 14:13 | comment | added | ratchet freak | then it isn't a valid sudoku, all 9 digits must occur exactly once, any symmetry (besides 360°) would require a number to occur twice | |
| May 16, 2014 at 14:12 | comment | added | user88 | The center square is symmetrical with itself. | |
| May 16, 2014 at 14:11 | comment | added | ratchet freak | rotationally symmetric how, just the center square stops it from being symmetric | |
| May 16, 2014 at 14:01 | history | asked | user88 | CC BY-SA 3.0 |