montyhall.clj

(ns montyhall
  (:require [clojure.set :as set]))

(defn make-a-deal [_]
  (let [doors (shuffle [:goat :goat :car])
        car? (= (doors (rand-int 3)) :car)]
    (if car? 1 0)))

(defn monty-hall [n]
  (let [first-guesses (reduce + 0
                              (map make-a-deal (range n)))]
    (format "keep: %.4f%% switch: %.4f%%"
            (float (/ first-guesses n))
             (float (/ (- n first-guesses) n)))))