davidgrenier

let toVarint v =
    let rec loop n s =
        match n >>> 7, n &&& 127 with
        | (0, c) -> byte c :: s
        | (r, c) -> loop r (byte (128 ||| c) :: s)
    loop v []

davidgrenier

#r @"System.Reactive.dll"

open System
open System.Reactive.Subjects
open System.Reactive.Linq

let run n m =
    let now = DateTime.Now

    let nodes = List.init n (fun _ -> new Subject<_>())

davidgrenier

open System

type Agent<'a> = MailboxProcessor<'a>
type Msg = Step of int | End

let getRingHead n =
    let lastNode =
        Agent.Start(fun inbox ->
            let rec loop (time : DateTime) = async {
                    let! m = inbox.Receive()

davidgrenier

let n = 1000;;

[1..n-1]
|> Seq.filter (fun v -> v % 3 = 0 || v % 5 = 0)
|> Seq.sum

davidgrenier

Seq.unfold (fun (c, n) -> Some(c, (n, c + n))) (1, 2)
|> Seq.takeWhile (fun v -> v <= 4000000)
|> Seq.filter (fun v -> v % 2 = 0)
|> Seq.sum

davidgrenier

let getLPF num =
    let rec getLPF l rest =
        seq { yield 2L; yield! seq {3L..2L..(rest |> float |> sqrt |> int64)}}
        |> Seq.tryFind (fun d -> rest % d = 0L)
        |> function
           | None -> max l rest
           | Some d -> getLPF (max l d) (rest / d)
    getLPF 1L num;;

getLPF 600851475143L

davidgrenier

let generate a b = seq {
        yield (a, b)
        let rec down (a, b) diff secondPass = seq {
                let next = a - diff, b + diff - 1
                yield next
                yield! up next diff (not secondPass)
            }
        and up (a,b) diff secondPass = seq {
                yield! Seq.init diff (fun i -> a + 1 + i, b - 1 - i)
                yield! down (a + diff, b - diff) (if secondPass then diff + 1 else diff) secondPass

davidgrenier

let sumOfSquares n =
    [1..n]
    |> Seq.map (fun x -> x * x)
    |> Seq.sum

let squareOfSum n =
    let v = [1..n] |> Seq.sum
    v * v

let diff n =

davidgrenier

let rec primes =
    let isPrime n =
        primes
        |> Seq.takeWhile (fun v -> v <= (float n |> sqrt |> int64))
        |> (not << Seq.exists (fun v -> n % v = 0L))
    let rec primes' n = seq {
        if isPrime n then
            yield n
        yield! primes' (n + 2L)
    }

davidgrenier

let source = 
    let src = @"73167176531330624919225119674426574742355349194934
96983520312774506326239578318016984801869478851843
85861560789112949495459501737958331952853208805511
12540698747158523863050715693290963295227443043557
66896648950445244523161731856403098711121722383113
62229893423380308135336276614282806444486645238749
30358907296290491560440772390713810515859307960866
70172427121883998797908792274921901699720888093776
65727333001053367881220235421809751254540594752243