15

diff --git a/15/one.icl b/15/one.icl
new file mode 100644 (file)
index 0000000..edbd103
--- /dev/null
+++ b/15/one.icl
@@ -0,0 +1,32 @@
+module one
+
+import Data.Maybe
+import StdEnv
+from Data.IntMap.Strict import :: IntMap
+import qualified Data.IntMap.Strict as DM
+
+input = [6,13,1,15,2,0]
+input2 = [0,3,6]
+
+Start = (one, two)
+
+one = speak 2020 input
+two = speak 30000000 input
+
+//Old part I version
+//speak :: Int [Int] -> Int
+//speak num inp = speak` num (reverse inp)
+//where
+//     speak` 0 spoken = spoken!!length inp
+//     speak` idx [ls:spoken] = case [i\\i<-[0..] & s<-spoken | s == ls] of
+//             [] = speak` (idx-1) [0,ls:spoken]
+//             [i:_] = speak` (idx-1) [i+1,ls:spoken]
+
+speak :: Int [Int] -> Int
+speak num inp = speak` (length inp) (last inp)
+       ('DM'.fromList [(num, idx)\\idx<-[0..] & num <-init inp])
+where
+       speak` :: !Int !Int !(IntMap Int) -> Int
+       speak` idx last spoken
+               | idx == num = last
+               = speak` (idx+1) (maybe 0 (\i->idx-i-1) ('DM'.get last spoken)) ('DM'.put last (idx-1) spoken)