September 2017 Update

Task/Monty-Hall-problem/BASIC/monty-hall-problem-2.basic

@@ -0,0 +1,15 @@
+ 10 PRINT "     WINS IF YOU"
+ 20 PRINT "STICK","SWITCH"
+ 30 LET STICK=0
+ 40 LET SWITCH=0
+ 50 FOR I=1 TO 1000
+ 60 LET CAR=INT (RND*3)
+ 70 LET GUESS=INT (RND*3)
+ 80 LET SHOW=INT (RND*3)
+ 90 IF SHOW=GUESS OR SHOW=CAR THEN GOTO 80
+100 LET NEWGUESS=INT (RND*3)
+110 IF NEWGUESS=GUESS OR NEWGUESS=SHOW THEN GOTO 100
+120 IF GUESS=CAR THEN LET STICK=STICK+1
+130 IF NEWGUESS=CAR THEN LET SWITCH=SWITCH+1
+140 PRINT AT 2,0;STICK,SWITCH
+150 NEXT I

Task/Monty-Hall-problem/Kotlin/monty-hall-problem.kotlin

@@ -0,0 +1,28 @@
+// version 1.1.2
+
+import java.util.Random
+
+fun montyHall(games: Int) {
+    var switchWins = 0
+    var stayWins = 0
+    val rnd = Random()
+    (1..games).forEach {
+        val doors = IntArray(3)        // all zero (goats) by default
+        doors[rnd.nextInt(3)] = 1      // put car in a random door
+        val choice = rnd.nextInt(3)    // choose a door at random
+        var shown: Int
+        do {
+            shown = rnd.nextInt(3)     // the shown door
+        }
+        while (doors[shown] == 1 || shown == choice)
+        stayWins += doors[choice]
+        switchWins += doors[3 - choice - shown]
+    }
+    println("Simulating $games games:")
+    println("Staying   wins $stayWins times")
+    println("Switching wins $switchWins times")
+}
+
+fun main(args: Array<String>) {
+    montyHall(1_000_000)
+}

Task/Monty-Hall-problem/Ring/monty-hall-problem.ring

@@ -0,0 +1,22 @@
+total = 10000
+swapper = 0
+sticker = 0
+revealdoor = 0
+for trial = 1 to total
+    prizedoor = random(3) + 1
+    guessdoor = random(3) + 1
+    if prizedoor = guessdoor
+       revealdoor = random(2) + 1
+       if prizedoor = 1 revealdoor += 1 ok
+       if (prizedoor = 2 and revealdoor = 2) revealdoor = 3 ok
+    else
+       revealdoor = (prizedoor ^ guessdoor)
+    ok
+    stickdoor = guessdoor
+    swapdoor = (guessdoor ^ revealdoor)
+    if stickdoor = prizedoor sticker += 1 ok
+    if swapdoor = prizedoor swapper += 1 ok
+next
+see "after a total of " + total + " trials," + nl
+see "the 'sticker' won " + sticker + " times (" + floor(sticker/total*100) + "%)" + nl
+see "the 'swapper' won " + swapper + " times (" + floor(swapper/total*100) + "%)" + nl

Task/Monty-Hall-problem/Rust/monty-hall-problem.rust

@@ -0,0 +1,26 @@
+extern crate rand;
+use rand::Rng;
+
+#[derive(Clone, Copy, PartialEq)]
+enum Prize {Goat , Car}
+
+const GAMES: usize = 3_000_000;
+fn main() {
+    let mut switch_wins = 0;
+    let mut rng = rand::thread_rng();
+
+    for _ in 0..GAMES {
+        let mut doors = [Prize::Goat; 3];
+        *rng.choose_mut(&mut doors).unwrap() = Prize::Car;
+
+        // You only lose by switching if you pick the car the first time
+        if rng.choose(&doors).unwrap() != &Prize::Car {
+            switch_wins += 1;
+        }
+    }
+    println!("I played the game {total} times and won {wins} times ({percent}%).",
+             total   = GAMES,
+             wins    = switch_wins,
+             percent = switch_wins as f64 / GAMES as f64 * 100.0
+    );
+}

Task/Monty-Hall-problem/Sidef/monty-hall-problem.sidef

@@ -1,21 +1,21 @@
-var n = 1000;                                 # number of times to play
-var switchWins = (var stayWins = 0);          # sum of each strategy's wins
-
+var n = 1000                                  # number of times to play
+var switchWins = (var stayWins = 0)           # sum of each strategy's wins
+ 
 n.times {                                     # play the game n times
-   var prize = 3.rand.int;
-   var chosen = 3.rand.int;
-
+   var prize = pick(^3)
+   var chosen = pick(^3)
+ 
    var show;
    do {
-        show = 3.rand.int
-   } while (show ~~ [chosen, prize]);
-
+        show = pick(^3)
+   } while (show ~~ [chosen, prize])
+ 
    given(chosen) {
      when (prize)                 { stayWins   += 1 }
      when ([3 - show - prize])    { switchWins += 1 }
      default                      { die "~ error ~" }
-    }
+   }
 }
-
-say ("Staying wins %.2f%% of the time."   % (100.0 * stayWins   / n));
-say ("Switching wins %.2f%% of the time." % (100.0 * switchWins / n));
+ 
+say ("Staying wins %.2f%% of the time."   % (100.0 * stayWins   / n))
+say ("Switching wins %.2f%% of the time." % (100.0 * switchWins / n))

Task/Monty-Hall-problem/Zkl/monty-hall-problem.zkl

@@ -0,0 +1,17 @@
+const games=0d100_000;
+
+reg switcherWins=0, keeperWins=0, shown=0;
+do(games){
+   doors := L(0,0,0);
+   doors[(0).random(3)] = 1; // Set which one has the car
+   choice := (0).random(3);  // Choose a door
+   while(1){ shown = (0).random(3);
+      if (not (shown == choice or doors[shown] == 1)) break; }
+   switcherWins += doors[3 - choice - shown];
+   keeperWins   += doors[choice];
+}
+
+"Switcher Wins: %,d (%3.2f%%)".fmt(
+   switcherWins, switcherWins.toFloat() / games * 100).println();
+"Keeper Wins: %,d (%3.2f%%)".fmt(
+   keeperWins, keeperWins.toFloat() / games * 100).println();