djoreilly · February 18, 2025 13:36 · Feb 18, 2025
diff --git a/monty-hall.py b/monty-hall.py
@@ -0,0 +1,39 @@
+# monty hall problem simulation https://en.wikipedia.org/wiki/Monty_Hall_problem
+
+import random
+
+ITERATIONS = 10000
+
+stick_count = 0
+stick_wins = 0
+switch_count = 0
+switch_wins = 0
+
+for _ in range(ITERATIONS):
+	doors = ["car", "goat", "goat"]
+	random.shuffle(doors)
+	car_idx = doors.index("car") 
+
+	# pick a random index into list doors. List indexes start at 0 and stop at len(doors)-1	
+	pick_idx = random.randint(0, 2)   # 0, 1 or 2
+
+	reveal_candidates = [0, 1, 2]
+	reveal_candidates.remove(pick_idx)
+	if car_idx != pick_idx:
+	    reveal_candidates.remove(car_idx)
+	reveal_idx = random.choice(reveal_candidates)
+
+	if random.choice(["stick", "switch"]) == "stick":
+		stick_count += 1
+		if pick_idx == car_idx:
+			stick_wins += 1
+	else:
+		switch_count += 1
+		if pick_idx != car_idx:
+			switch_wins += 1
+
+
+stick_win_pc = stick_wins / stick_count * 100
+print(f"stick win percentage: {stick_wins}/{stick_count} = {stick_win_pc:.2f}%")
+switch_win_pc = switch_wins / switch_count * 100
+print(f"switch win percentage: {switch_wins}/{switch_count} = {switch_win_pc:.2f}%")
diff --git a/run.md b/run.md
@@ -0,0 +1,5 @@
+```
+$ python3 monty-hall.py 
+stick win percentage: 1610/4975 = 32.36%
+switch win percentage: 3271/5025 = 65.09%
+```