Igloo (8x8)
(Published on 4. February 2026, 16:04 by Mr Toffee)
Slow-Thermo Sudoku
(O) Bulbs ≤ Tips ( I )
Digits must never decrease along thermometers from bulb to tip.
...Digits may therefore repeat along thermometers.
Flows may merge or diverge, but must always end at a given tip.
Colours are not part of the puzzle.
Flow must be determined.
Try the puzzle here
Solution code: Row 1 from left to right
Comments
on 6. February 2026, 14:48 by PinkNickels
Fun one! Fortunately, i was correct on my initial thought on flow. otherwise could have gotten tricky!
on 5. February 2026, 16:53 by Mr Toffee
Added the rule bit... flow must be determined!
on 5. February 2026, 15:46 by tjmas
In the solution code, there is a place where the thermo decreases from bulb to tip, no? I do not believe it is solvable without this, either. Am I missing something?
Spoiler (if im wrong):
Row 5 column 6 / row 5 column 7
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Hiya, I missed "flows must be determined" from the ruleset, perhaps mistakenly...
spoiler alert
-- r5c1 can't 'hit' r7c5, so direction is up northwesterly r5c7 - r3c4 --- the 2/3 in r6c8 then limits r7c4 thermo, so r5c5 + r5c7 both 'feed' the 'flow' r5c6 - r7c5 thermo tip...
Flow or flüsse, which I think means rivers, is the get out clause... flow must be determined... In jeder Situation muss der Fluss gefunden werden. I have just now put it back in the rules.
There used to be valves to direct flows because I thought the thermo rule was absolute in every direction, and that this kind of thing broke the puzzles due to that, but that direction uncertainty, the mercurial flower, has become a fog of sorts, so that it doesn't give up its secrets immediately all at once... which is nice for a ruletype commonly known for having everything given away all at once.
on 4. February 2026, 19:36 by Titan29
Pretty new to the whole merging and diverging thermos thing, at least when the merging and diverging is this ambiguous. I figured it out though, nice little puzzle!
on 4. February 2026, 17:51 by Mr Toffee
Ooo, well spotted, I have amended the puzzle design to solve without ambiguity.
