Logic Masters Deutschland e.V.

COP26 (indexing madness) [draw your own thermo sudoku]

(Published on 15. March 2022, 18:06 by SimplePurpleFrog)

This puzzle does not need bifurcation, long chains, nor does it require full pencil marks.

This 'draw your own thermo' puzzle, with added RC indexing, represents the madness of global warming, thermometers out in the wild, yet, under the index!

Rules:

  • Normal Sudoku rules apply.
  • The orange line is an equal sums line: the digits in each 3x3 box on this line sum to the same total;
  • Cages: digits sum to the total indicated in the top-left corner;
  • Domino cages: the row number (horizontal) or column number (vertical) is the digit to be placed at the row and column indicated by the digits in the cage;
  • In yellow cages the solver must determine which digit is the row and which is the column;
  • Blue cages must be read both ways.
  • Indexed thermos:
    • Short version:
      • There is a thermo on each row/column;
      • The lowest of the first and last digits indexes the thermo's bulb, counting from the low side;
      • The highest indexes the tip;
      • No two thermos share a cell.
    • Long version:
      • On each row, the digits in the first and last column index the bulb and tip of a thermo.
      • The lower of the two index digits indicates the column where the bulb must be placed, counting columns from the low digit.
      • The higher digit indexes the tip, also counting from the low digit.
      • The thermo goes in a straight line from bulb to tip.
      • On a thermo digits increase from the bulb to the tip.
      • Similarly on each column, the digits in the first and last row index the bulb and the tip of a thermo, counting from the low digit.
      • Thermos do not share any cell.

Check the graphic after the puzzle for further examples.

Play COP26 on F-Puzzles or CtC (colour blind friendly).

Please let me know how you get on.

Example RC indexing: e.g. a horizontal yellow domino in r4c5c6. r4 means the digit to be placed is a 4 (we check the row because the domino is horizontal, otherwise we check the column), the digit in r4c5 is either the row or the column indexed, the digit in r4c6 is either the column or the row indexed, at that RC, place the digit 4.

Example indexed thermo: Say digit 7 is in r4c1 and digit 5 in r4c9, then, in row 4, the thermo starts from the right (because 5 is lower than 7 and in column 9) on the 5th cell from the right is the bulb of the thermo, going straight to the tip of the thermo in the 7th cell from the right.


Full 7x7 grid working example (the smallest possible grid that can have full thermo indexing):

You can even play the example on F-Puzzles

Or play COP26 on F-Puzzles or CtC (colour blind friendly).


Further examples of RC and thermo indexing, below.

To note: the yellow cages below show one of two valid possibilities only, but only one is correct at once.


Below is version 1 of the puzzle, more complicated rules, easier solve but less interesting. Keeping it for reference as it essentially is the same puzzle, same solution, and I value early testers.

V1 rules differ by the following:

  • Green cages read from left to right or top to bottom, row first;
  • Red cages read in the opposite direction;

Examples of RC and thermo indexing:

V1 (less interesting) on F-Puzzles or CtC.

V2 (better) on F-Puzzles or CtC.

Additional tags: RC indexing, Indexed thermometers.

Ich wäre Ihnen dankbar, wenn mir jemand eine Übersetzung meines Rãtsel ins Deutsche zur Verfügung stellen würde.

Solution code: All digits in column 6, then row 7.

Last changed on on 6. April 2022, 22:50

Solved by ClashCode, kublai, purpl, cristophermoore, Vebby, SirSchmoopy
Full list

Comments

on 25. April 2022, 03:42 by SirSchmoopy
I loved this! Absolutely brilliant. That such a grid even is possible is amazing, but to have a grid like this with a logical solve path is stunning.

Would love to see more puzzles with this constraint

on 6. April 2022, 22:49 by SimplePurpleFrog
Full grid example

Last changed on 18. March 2022, 02:45

on 18. March 2022, 02:23 by SimplePurpleFrog
Version 2 of the puzzle, slightly simpler rules, slightly more challenging solve, much more interesting - thank you @Plostoni for this suggestion.

on 17. March 2022, 06:26 by cristophermoore
It took me a while to get used to the indexing, but then it was smooth and fun! And great theme.

on 16. March 2022, 21:10 by SimplePurpleFrog
Thermo example text

on 16. March 2022, 20:10 by kublai
I restarted this puzzle several times before I realized the indexing for the thermo starts from the side with the lower number. (Yes, I now see that covered in the example). Nice puzzle!

on 16. March 2022, 15:09 by ClashCode
I really enjoyed the puzzle!
Took me a minute to understand the rules but the deductions were fairly smooth afterwards.

on 16. March 2022, 15:05 by SimplePurpleFrog
Solution code corrected

Difficulty:3
Rating:N/A
Solved:6 times
Observed:7 times
ID:0009DJ

Puzzle variant Variant combination New

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Solution code:

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