theburningmonk

open System.Text
open System.Security.Cryptography

let input = "udskfozm"
let width, height = 4, 4

let md5 = CryptoConfig.CreateFromName("MD5") :?> HashAlgorithm

let hash (input : string) =
  let bytes = input |> Encoding.UTF8.GetBytes |> md5.ComputeHash

theburningmonk

let part1 = findPaths input |> Seq.tryHead

theburningmonk

let part2 = findPaths input |> Seq.map String.length |> Seq.max

theburningmonk

open System
open System.Text
open System.Security.Cryptography

let input = "udskfozm"
let width, height = 4, 4

let md5 = CryptoConfig.CreateFromName("MD5") :?> HashAlgorithm

let hash (input : string) =

theburningmonk

let input = "11011110011011101" |> Seq.map ((=) '1') |> Seq.toArray

let solve diskSize input =
  let rec dragonCurve (a : bool[]) =
    if a.Length >= diskSize 
    then a.[0..diskSize-1]
    else  
      [|
        yield! a
        yield false

theburningmonk

let input2 = input1 @ [ { Number = 7; Positions = 11; Time0Pos = 0 } ]
let part2  = solve input2

theburningmonk

type Disc = 
  {
    Number    : int
    Positions : int
    Time0Pos  : int
  }

let solve (discs : Disc list) = 
  // what's the first time we can press and get through the first slot?
  let fstDisc    = discs.[0]

theburningmonk

let hex = 
  seq {
    yield! Seq.zip { 0uy..9uy } { '0'..'9' }
    yield! Seq.zip { 10uy..15uy } { 'a'..'f' }
  }
  |> Map.ofSeq

let hash (input : string) =
  let bytes = input |> Encoding.UTF8.GetBytes |> md5.ComputeHash
  let chars = Array.zeroCreate<char> (bytes.Length * 2)

theburningmonk

let keyStretch (input : string) =
  { 0..2016 } |> Seq.fold (fun last _ -> hash last) input

let part2 = solve keyStretch

theburningmonk

open System
open System.Collections.Generic
open System.Text
open System.Security.Cryptography

let input = "ahsbgdzn"

let md5 = CryptoConfig.CreateFromName("MD5") :?> HashAlgorithm

let hash (input : string) =