> module Sudokus where


> type Sudoku = [Integer]

if there are no more 0s then we are all done!

> solved s = 0 `notElem` s

Replace the 0 by the move you are making


> choose s (cell, mov) = zipWith choose' s [0..]
>   where
>     choose' digit index | cell == index = mov
>                         | otherwise     = digit

> choices s = zip (repeat zeroCells) (posDigits s zeroCells)
>   where
>     zeroCells = case filter isZero (zip s [0..]) !! 0 of
>                   (0, index) -> index
>       where
>         isZero (digit, index) = digit == 0

these need to probably be edited for squig:

posDigits are the digits which are not in a cell already

> posDigits s cell = [digit | digit <- [1..9], free digit]
>   where
>     free digit = digit `notElem` [s !! x | x <- indices cell]

> indices n = col n ++ row n ++ box n

> col     n = take 8 [x   | x <- [n `mod` 9, n `mod` 9 + 9 ..], x   /= n]
> row     n = take 8 [x   | x <- [n - n `mod` 9 ..],            x   /= n]
> --box     n =        [x+y | x <- rows, y <- cols,               x+y /= n]
> box     n = findBoxIndexes n makeSquigelyBoxes
>   where
>     rows = take 3 [n - n `mod` 27, n - n `mod` 27 + 9 ..]
>     cols = take 3 [n `mod` 9 - n `mod` 3 ..]

> squ1 = [0,1,2,9,11,18,20,27,29]
> squ2 = map (+3) squ1
> squ3 = map (+3) squ2
> squ4 = [10,19,28,36,37,38,46,55,64]
> squ5 = map (+3) squ4
> squ6 = map (+3) squ5
> squ7 = [45,47,54,56,63,65,72,73,74]
> squ8 = map (+3) squ7
> squ9 = map (+3) squ8

> makeSquigelyBoxes = squ1 : squ2 : squ3 : squ4 : squ5 : squ6 : squ7 : squ8 : squ9 : []

> findBoxIndexes _ [] = error "There was a problem"
> findBoxIndexes a xs = filter (a /= ) $ head $ filter (a `elem`) xs