Reimar/adventofcode-2024
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Solve day 2 part 2

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This commit is contained in:
Reimar 2024-12-04 17:56:12 +01:00
parent 67aea117c3
commit 67fd4e2085
Signed by: Reimar
GPG Key ID: 93549FA07F0AE268
1 changed files with 18 additions and 2 deletions
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20
day_2.sml
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@ -1,9 +1,15 @@
fun isDecreasing (l: int list) : bool =
fun deleteNth (l : int list, n : int) = List.take (l, n) @ List.drop (l, n + 1)
fun isDecreasing (l : int list) =
ListPair.all (fn (a, b) => b < a andalso b >= a - 3) (l, tl l)
fun isIncreasing (l: int list) : bool =
fun isIncreasing (l : int list) =
ListPair.all (fn (a, b) => b > a andalso b <= a + 3) (l, tl l)
fun withTolerance (f : (int list) -> bool) = fn (l : int list) =>
let val withRemoved = List.tabulate (List.length l, fn (i) => deleteNth (l, i))
in List.exists f withRemoved end
val file = TextIO.openIn "day_2.txt"
val input = TextIO.inputAll file;
TextIO.closeIn file;
@ -17,7 +23,17 @@ val reports = map
)
lines
(* Part 1 *)
val safeReports = List.filter (fn (report) => isDecreasing report orelse isIncreasing report) reports
val safeAmount = List.length safeReports
(* Part 2 *)
val toleratedReports = List.filter
(fn (report) => withTolerance isDecreasing report orelse withTolerance isIncreasing report)
reports
val toleratedAmount = List.length toleratedReports