Data commit

Task/Monty-Hall-problem/F-Sharp/monty-hall-problem-1.fs

@@ -0,0 +1,13 @@
+open System
+let monty nSims =
+    let rnd = new Random()
+    let SwitchGame() =
+        let winner, pick = rnd.Next(0,3), rnd.Next(0,3)
+        if winner <> pick then 1 else 0
+
+    let StayGame() =
+        let winner, pick = rnd.Next(0,3), rnd.Next(0,3)
+        if winner = pick then 1 else 0
+
+    let Wins (f:unit -> int) = seq {for i in [1..nSims] -> f()} |> Seq.sum
+    printfn "Stay: %d wins out of %d - Switch: %d wins out of %d" (Wins StayGame) nSims (Wins SwitchGame) nSims

Task/Monty-Hall-problem/F-Sharp/monty-hall-problem-2.fs

@@ -0,0 +1,32 @@
+let montySlower nSims =
+    let rnd = new Random()
+    let MontyPick winner pick =
+        if pick = winner then
+            [0..2] |> Seq.filter (fun i -> i <> pick) |> Seq.nth (rnd.Next(0,2))
+        else
+            3 - pick - winner
+    let SwitchGame() =
+        let winner, pick = rnd.Next(0,3), rnd.Next(0,3)
+        let monty = MontyPick winner pick
+        let pickFinal = 3 - monty - pick
+
+        // Show that Monty's pick has no effect...
+
+        if (winner <> pick) <> (pickFinal = winner) then
+            printfn "Monty's selection actually had an effect!"
+        if pickFinal = winner then 1 else 0
+
+    let StayGame() =
+        let winner, pick = rnd.Next(0,3), rnd.Next(0,3)
+        let monty = MontyPick winner pick
+
+        // This one's even more obvious than the above since pickFinal
+        // is precisely the same as pick
+
+        let pickFinal = pick
+        if (winner = pick) <> (winner = pickFinal) then
+            printfn "Monty's selection actually had an effect!"
+        if winner = pickFinal then 1 else 0
+
+    let Wins (f:unit -> int) = seq {for i in [1..nSims] -> f()} |> Seq.sum
+    printfn "Stay: %d wins out of %d - Switch: %d wins out of %d" (Wins StayGame) nSims (Wins SwitchGame) nSims