gistfile1.txt

import random

sample_size = 10_000

stay_wins = 0
switch_wins = 0

for _ in range(sample_size):
    prize = random.randint(1, 3)
    pick = random.randint(1, 3)

    # Host reveals an empty door (not the prize, not your pick)
    remaining = [d for d in [1, 2, 3] if d != pick and d != prize]
    host_opens = random.choice(remaining)

    if pick == prize:
        stay_wins += 1      # Staying wins when original pick was right
    else:
        switch_wins += 1    # Switching wins every other time

print(f"Stay:   {stay_wins}/{sample_size} wins ({100 * stay_wins / sample_size:.2f}%)")
print(f"Switch: {switch_wins}/{sample_size} wins ({100 * switch_wins / sample_size:.2f}%)")