https://zh.wikipedia.org/wiki/%E8%92%99%E6%8F%90%E9%9C%8D%E7%88%BE%E5%95%8F%E9%A1%8C

x.py

#coding=utf-8
# https://zh.wikipedia.org/wiki/%E8%92%99%E6%8F%90%E9%9C%8D%E7%88%BE%E5%95%8F%E9%A1%8C
import sys
import random

stay = 0
change = 0
MAX_TRY = int(sys.argv[1])

for i in range(MAX_TRY):
    # 大奖
    real = random.randint(0, 2)

    # 选择
    choice = random.randint(0, 2)

    # 主持人打开一个没有奖品的门之后，面临两种选择，坚持或者改变
    # 坚持选择时，获胜的情况仅为 real == choice
    # 当 real != choice 时，改变可以获得大奖
    if real == choice:
        stay += 1
    else:
        change += 1

print(float(stay)/MAX_TRY, float(change)/MAX_TRY)