From: Mart Lubbers <mart@martlubbers.net>
Date: Tue, 22 Dec 2020 15:09:28 +0000 (+0100)
Subject: 22
X-Git-Url: https://git.martlubbers.net/?a=commitdiff_plain;p=aoc20.git

22
---

diff --git a/22/input b/22/input
new file mode 100644
index 0000000..4046004
--- /dev/null
+++ b/22/input
@@ -0,0 +1,53 @@
+Player 1:
+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
+
+Player 2:
+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
diff --git a/22/one.icl b/22/one.icl
new file mode 100644
index 0000000..7182c60
--- /dev/null
+++ b/22/one.icl
@@ -0,0 +1,42 @@
+module one
+
+import StdEnv, StdDebug
+import Data.Either
+
+input :: ([Int], [Int])
+input =
+	([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]
+	,[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]
+	)
+
+//input :: ([Int], [Int])
+//input =
+//	([ 9, 2, 6, 3, 1]
+//	,[ 5, 8, 4, 7, 10]
+//	)
+
+Start = (uncurry combat input, uncurry rcombat input [] [])
+
+combat :: [Int] [Int] -> Either Int Int
+combat [] b = Right (score b)
+combat a [] = Left (score a)
+combat [a:as] [b:bs]
+	| a > b     = combat (as ++ [a,b]) bs
+	| a < b     = combat as (bs ++ [b,a])
+	| otherwise = abort "draw"
+
+score :: [Int] -> Int
+score d = sum [i*d\\d<-reverse d & i<-[1..]]
+
+rcombat :: [Int] [Int] [[Int]] [[Int]] -> Either Int Int
+rcombat [] b _ _ = Right (score b)
+rcombat a [] _ _ = Left (score a)
+rcombat [a:as] [b:bs] ahist bhist
+	| isMember [a:as] ahist && isMember [b:bs] bhist = Left (score [a:as])
+	# (ahist, bhist) = ([[a:as]:ahist], [[b:bs]:bhist])
+	| a <= length as && b <= length bs
+		= case rcombat (take a as) (take b bs) [] [] of
+			Left s  = rcombat (as ++ [a,b]) bs ahist bhist
+			Right s = rcombat as (bs ++ [b,a]) ahist bhist
+	| a > b = rcombat (as ++ [a,b]) bs ahist bhist
+	| a < b = rcombat as (bs ++ [b,a]) ahist bhist