Dirty simulation to Monty Hall Problem

Main.scala

package me.occ.dealornodeal

import scala.util.Random

object Main extends App {
  val rng = new Random()

  def runTrial(changeMind: Boolean, showOutput: Boolean = false): Boolean = {
    val prize = rng.nextInt(3)
    var options = Seq.range(0, 3).map(_ == prize).zipWithIndex
    if (showOutput) println(s"Stage: $options")

    val initialGuess = options(rng.nextInt(3))
    if (showOutput) println(s"Guess: $initialGuess")

    val toEliminate = options.find(t => !t._1 && t != initialGuess).get
    options = options.filterNot(_ == toEliminate)
    if (showOutput) println(s"Remaining: $options")

    val nextGuess = if (!changeMind) initialGuess else options.find(_ != initialGuess).get

    if (showOutput) {
      print(s"Final guess: $nextGuess -- ")
      if (nextGuess._1) println("Win") else println("Lose")
    }

    nextGuess._1
  }

  def runNTrials(n: Int, changeMind: Boolean): Unit = {
    val win: Int = Seq.range(0, n).map(x => runTrial(changeMind)).count(_ == true)
    val lose = n - win
    println(s"Win: $win, Lose: $lose. Total: ${win.toDouble/n}")
  }

  runNTrials(1000000, changeMind = true)
}