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# Difference between revisions of "Sudoku/Puzzles/Inkala's Maze"

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==Interesting pages== | ==Interesting pages== | ||

− | *[http://www.aisudoku.com/index_en.html AI | + | *[http://www.aisudoku.com/index_en.html AI Sudoku]. The horses' mouth. This will warrant more study. [[/AI Sudoku]] He runs a difficulty measure on a few sudoku. |

:His "10 hardest" do not appear to include the original "World's Hardest." He never mentions this. He is selling his work, and specifically requires permission, so unless he grants it, I will not be publishing worksheets, but will describe solution paths as found. | :His "10 hardest" do not appear to include the original "World's Hardest." He never mentions this. He is selling his work, and specifically requires permission, so unless he grants it, I will not be publishing worksheets, but will describe solution paths as found. | ||

:He has a method he calls AIroot, which is probably what other sites call "[https://en.wikipedia.org/wiki/Ariadne%27s_thread_(logic)#Applications Ariadne's Thread]." [in that Wikipedia article, notice the unsourced judgmental claim.] He seems to be unaware of this. Ariadne's Thread must solve every Sudoku, it is logically required, if there is a solution, regardless of the first choice made. His estimate of the difficulty may not factor for a more efficient application of advanced techniques, such as AT or Simultaneous Binary Nisho, and especially for a hybrid approach, which a manual solver will use. We will see what we find. The unconditional solver on Sudokuwiki shows the number of steps taken to solve a puzzle, but that solver almost certainly uses a fixed algorithm to make the choice, and almost certainly does not optimize them, beyond the current candidate list. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 20:05, 25 June 2019 (UTC) | :He has a method he calls AIroot, which is probably what other sites call "[https://en.wikipedia.org/wiki/Ariadne%27s_thread_(logic)#Applications Ariadne's Thread]." [in that Wikipedia article, notice the unsourced judgmental claim.] He seems to be unaware of this. Ariadne's Thread must solve every Sudoku, it is logically required, if there is a solution, regardless of the first choice made. His estimate of the difficulty may not factor for a more efficient application of advanced techniques, such as AT or Simultaneous Binary Nisho, and especially for a hybrid approach, which a manual solver will use. We will see what we find. The unconditional solver on Sudokuwiki shows the number of steps taken to solve a puzzle, but that solver almost certainly uses a fixed algorithm to make the choice, and almost certainly does not optimize them, beyond the current candidate list. --[[User:Abd|Abd]] ([[User talk:Abd|talk]]) 20:05, 25 June 2019 (UTC) |

## Latest revision as of 04:30, 2 December 2019

**Inkala's Maze**was invented by Arto Inkala, a Finnish mathematician. (Load sudoku into the SudokuWiki Solver).

## News coverage[edit]

- From [1]: Worlds-hardest-sudoku-can-you-crack-it]
*The Telegraph*. Dead link. Archive.org is down.Worlds-hardest-sudoku-can-you-crack-it - From [2]: Maths-whiz-Dr-Arto-Inkala-creates-hardest-Sudoku-yet
*The Sun*. Link redirects to home page. - From [3]: mathematician-arto-inkala-creates-worlds-hardest-sudoku-everest
*Metro*. Dead link. - can-you-crack-the-worlds-toughest-sudoku
*Fox News*. Apparently Inkala, after claiming the "world's toughest sudoku" in 2006 or so, four years later claimed a tougher one. This is a scientist? Just asking! According to Andrew Stuart, writing contemporaneously, it is not difficult to create insanely difficult Sudoku, and he lists four, with Inkala's Maze being in third place. Back then. --Abd (talk) 19:36, 25 June 2019 (UTC) - It-took-months-create-long-crack--worlds-hardest-Sudoku
*Daily Mail.*

- 'Some people might make three or four lucky guesses and so be able to solve it in 15 minutes or half an hour and will wonder why it is said to be so difficult.

- 'But it will normally take days to solve by logic.'
- Inkala perhaps does not understand that logic includes identifying likely solutions There are logical algorithms and intuitional heuristics. If this takes days to solve, someone is not using efficient logic nor informed heuristics. But we will test this claim. Not described in any article so far, how Inkala decides "world's hardest"? But I think it is on his web site. --Abd (talk) 19:36, 25 June 2019 (UTC)

## Interesting pages[edit]

- AI Sudoku. The horses' mouth. This will warrant more study. /AI Sudoku He runs a difficulty measure on a few sudoku.

- His "10 hardest" do not appear to include the original "World's Hardest." He never mentions this. He is selling his work, and specifically requires permission, so unless he grants it, I will not be publishing worksheets, but will describe solution paths as found.
- He has a method he calls AIroot, which is probably what other sites call "Ariadne's Thread." [in that Wikipedia article, notice the unsourced judgmental claim.] He seems to be unaware of this. Ariadne's Thread must solve every Sudoku, it is logically required, if there is a solution, regardless of the first choice made. His estimate of the difficulty may not factor for a more efficient application of advanced techniques, such as AT or Simultaneous Binary Nisho, and especially for a hybrid approach, which a manual solver will use. We will see what we find. The unconditional solver on Sudokuwiki shows the number of steps taken to solve a puzzle, but that solver almost certainly uses a fixed algorithm to make the choice, and almost certainly does not optimize them, beyond the current candidate list. --Abd (talk) 20:05, 25 June 2019 (UTC)
- AI Sudoku Top10 set:1 donation requested.
- AI Sudoku Conflict Examples donation requested.

- solving_the_hardest_sudoku? IBM.com/developerworks.
- worlds-hardest-sudoku] yet another, apparently from Inkala, no date or link, but it is AI Escargot, which he rated as toughest, years ago.

## Commentary[edit]

See Arto Inakala Sudoku on Sudokuwiki, a review by Andrew Stuart, and commentary on the review is here

/Solution process will cover how to solve Inkala's Maze and similar puzzles.