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HomePureScript solution to Project Euler problem 11
2018-Aug-01 09:18
Problem details at Project Euler problem 11 page.
Test
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 | module Euler011Test (euler11suite) where import Prelude import Data . Maybe ( Maybe ( .. )) import Euler011 (euler11) import Test . Unit (TestSuite, suite, test) import Test . Unit . Assert as Assert gridWarmup :: String gridWarmup = "" " 08 02 22 97 49 49 99 40 81 49 31 73 52 70 95 23 "" " gridReal :: String gridReal = "" " 08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08 49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00 81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65 52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91 22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80 24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50 32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70 67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21 24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72 21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95 78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92 16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57 86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58 19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40 04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66 88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69 04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36 20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16 20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54 01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48 "" " euler11suite :: forall e . TestSuite e euler11suite = suite "Euler 11" do test "Warmup" do Assert . equal ( Just 24468444 ) (euler11 gridWarmup) test "Real" do Assert . equal ( Just 70600674 ) (euler11 gridReal) |
Solution
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 | module Euler011 (euler11) where import Prelude import Data . Array (catMaybes, concat , drop , filter , head , length , null , range, reverse , take , zip , ( : )) import Data . Foldable ( maximum , product ) import Data . Int (fromString) import Data . Maybe ( Maybe , maybe ) import Data . String (Pattern( .. ), split, trim) import Data . Tuple ( Tuple ( .. )) lines :: String - > Array String lines = split (Pattern "\n" ) <<< trim words :: String - > Array String words = split (Pattern " " ) <<< trim type Mat a = Array ( Array a) toMat :: String - > Mat Int toMat s = catMaybes < $ > map fromString < $ > words < $ > lines s filterEmpty :: forall a . Mat a - > Mat a filterEmpty m = filter ( not <<< null ) m visit1 :: forall a . (Mat a - > Mat a) - > Mat a - > Mat a visit1 f m = filterEmpty ( concat $ f < $ > tails m) visit :: forall a . (Mat a - > Mat a) - > Mat a - > Mat a visit _ [] = [] visit f m = visit1 f m <> visit f (filterEmpty $ drop 1 < $ > m) transpose :: forall a . Mat a - > Mat a transpose m = visit f m where f x = take 1 < $ > x flipVer :: forall a . Mat a - > Mat a flipVer = liftA1 reverse tails :: forall a . Mat a - > Array (Mat a) tails [] = [] tails m = m : tails ( drop 1 m) horiz :: Int - > Mat Int - > Array Int horiz n m = maybe [] ( take n) ( head m) diag :: Int - > Mat Int - > Array Int diag n m = let ts = zip (range 0 (n - 1 )) ( take n m) f ( Tuple i a) = drop i a sm = f < $ > ts in catMaybes $ head < $ > sm hordi :: Int - > Mat Int - > Mat Int hordi n m = filter f [horiz n m, diag n m] where f e = length e == n euler11 :: String - > Maybe Int euler11 s = let m = toMat s ms = [m, flipVer m, transpose m] f = hordi 4 vs = concat $ visit f < $ > ms ps = product < $ > vs in maximum ps |