Hall Paradox

Demonstration Hall Paradox Game1 xxx - 1 strategy; Game2 xxx - 2 strategy (change choice).

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open System
let Game1 count=
  let rnd=new Random()
  List.init count (fun _ ->rnd.Next(3))
    |>List.fold (fun a x->x|>function
                       |x when x=rnd.Next(3)->a+1
                       |_->a)
                0|>printf "%d wins\n"
let Game2 count=
  let rnd=new Random()
  List.init count (fun _ ->rnd.Next(3))
    |>List.fold (fun a x->x|>function
                       |x when x=rnd.Next(3)->a
                       |_->a+1)
                0|>printf " %d wins\n"
//> Game1 1000;;
//> 317 wins
//val it : unit = ()
//> Game2 1000;;
//> 668 wins
//val it : unit = ()

namespace System

val Game1 : count:int -> unit

Full name: Script.Game1

val count : int

val rnd : Random

Multiple items
type Random =
  new : unit -> Random + 1 overload
  member Next : unit -> int + 2 overloads
  member NextBytes : buffer:byte[] -> unit
  member NextDouble : unit -> float

Full name: System.Random

--------------------
Random() : unit
Random(Seed: int) : unit

Multiple items
module List

from Microsoft.FSharp.Collections

--------------------
type List<'T> =
  | ( [] )
  | ( :: ) of Head: 'T * Tail: 'T list
  interface IEnumerable
  interface IEnumerable<'T>
  member Head : 'T
  member IsEmpty : bool
  member Item : index:int -> 'T with get
  member Length : int
  member Tail : 'T list
  static member Cons : head:'T * tail:'T list -> 'T list
  static member Empty : 'T list

Full name: Microsoft.FSharp.Collections.List<_>

val init : length:int -> initializer:(int -> 'T) -> 'T list

Full name: Microsoft.FSharp.Collections.List.init

Random.Next() : int
Random.Next(maxValue: int) : int
Random.Next(minValue: int, maxValue: int) : int

val fold : folder:('State -> 'T -> 'State) -> state:'State -> list:'T list -> 'State

Full name: Microsoft.FSharp.Collections.List.fold

val a : int

val x : int

val printf : format:Printf.TextWriterFormat<'T> -> 'T

Full name: Microsoft.FSharp.Core.ExtraTopLevelOperators.printf

val Game2 : count:int -> unit

Full name: Script.Game2

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More information

Link:	http://fssnip.net/nO
Posted:	10 years ago
Author:	Zhukoff Dima
Tags:	mathematic