2025-12-02 20:10:20 +00:00

42 lines
1.2 KiB
Forth

module advent_of_code.tasks.day_2.Star2
open System.IO
let stream = new StreamReader("tasks/day-2/input.txt")
let convertToString (i: int64) = i |> string
let divideString (str: string) (n: int) =
let count = str.Length / n
let mutable parts = Set.empty
for i in 0 .. count - 1 do
let start = i * n
parts <- parts.Add(str.Substring(start, n))
parts
let rec isInvalid (id: string) (chars: int) =
let biggerSlices = if chars = id.Length then 0 |> int64 else isInvalid id (chars + 1)
if (chars = id.Length) then
0
else if (biggerSlices <> 0) then
biggerSlices
else if (id.Length % chars <> 0) then
0
else
let parts = divideString id chars
if parts.Count = 1 then id |> int64 else 0
let checkValid (id: string) = isInvalid id 1
let rec getInvalid (lines: string list) =
let line, tail = lines.Head, lines.Tail
let els = line.Split("-")
let low, high = els[0] |> int64, els[1] |> int64
let invalids = [low .. high] |> List.map convertToString |> List.map checkValid
List.sum invalids + if tail.IsEmpty then 0 |> int64 else getInvalid tail
let main =
let lines = stream.ReadLine().Split(",") |> Array.toList
getInvalid lines