22/one.icl

   1 module one
   2
   3 import StdEnv, StdDebug
   4 import Data.Either
   5
   6 input :: ([Int], [Int])
   7 input =
   8         ([45,10,43,46,25,36,16,38,30,15,26,34,9,2,44,1,4,40,5,24,49,3,41,19,13]
   9         ,[28,50,37,20,6,42,32,47,39,22,14,7,21,17,27,8,48,11,23,12,18,35,29,33,31]
  10         )
  11
  12 //input :: ([Int], [Int])
  13 //input =
  14 //      ([ 9, 2, 6, 3, 1]
  15 //      ,[ 5, 8, 4, 7, 10]
  16 //      )
  17
  18 Start = (uncurry combat input, uncurry rcombat input [] [])
  19
  20 combat :: [Int] [Int] -> Either Int Int
  21 combat [] b = Right (score b)
  22 combat a [] = Left (score a)
  23 combat [a:as] [b:bs]
  24         | a > b     = combat (as ++ [a,b]) bs
  25         | a < b     = combat as (bs ++ [b,a])
  26         | otherwise = abort "draw"
  27
  28 score :: [Int] -> Int
  29 score d = sum [i*d\\d<-reverse d & i<-[1..]]
  30
  31 rcombat :: [Int] [Int] [[Int]] [[Int]] -> Either Int Int
  32 rcombat [] b _ _ = Right (score b)
  33 rcombat a [] _ _ = Left (score a)
  34 rcombat [a:as] [b:bs] ahist bhist
  35         | isMember [a:as] ahist && isMember [b:bs] bhist = Left (score [a:as])
  36         # (ahist, bhist) = ([[a:as]:ahist], [[b:bs]:bhist])
  37         | a <= length as && b <= length bs
  38                 = case rcombat (take a as) (take b bs) [] [] of
  39                         Left s  = rcombat (as ++ [a,b]) bs ahist bhist
  40                         Right s = rcombat as (bs ++ [b,a]) ahist bhist
  41         | a > b = rcombat (as ++ [a,b]) bs ahist bhist
  42         | a < b = rcombat as (bs ++ [b,a]) ahist bhist