Question

我一直在尝试写出一个问题出生日。假设人们进入一个空房间直到一对人过生日。平均而言，一场比赛之前，有多少人必须进入？编写一个程序Birthday.py，该程序接受试验（int）作为命令行参数，运行试验实验以估计此数量-每个实验都涉及对个体进行采样直到一对他们中的一个人过生日，并将值写到标准输出中。我的麻烦一直是获得输出。如果我在命令终端中输入1000，则应该输出24，但它不会给出任何信息。

DAYS_PER_YEAR = 365
    
    # Accept trials (int) as command-line argument.
    trials = int(sys.argv[1])
    
    # Set count, denoting the total number of individuals sampled across the trials number of
    # experiments, to 0.
    total = 0
    
    for i in range(trials):
        # Perform trials number of experiments, where each experiment involves sampling individuals
        # until a pair of them share a birthday...
    
        # Setup a 1D list birthdaysSeen of DAYS_PER_YEAR Booleans, all set to False by default. This
        # list will keep track of the birthdays encountered in this experiment.
        birthdaysSeen = stdarray.create1D(DAYS_PER_YEAR, False)
        while True:
            # Sample individuals until match
            n = stdrandom.uniformInt(0, 364)
            # Increment count by 1.
            total += 1
    
            # Set birthday to a random integer from [0, DAYS_PER_YEAR).
            birthday = stdrandom.uniformInt(0, DAYS_PER_YEAR)
    
            if birthdaysSeen[birthday]:
                # If birthday has been encountered, abort this experiment, ie, break.
                break
        else:
            # Record the fact that we are seeing this birthday for the first time.
            birthdaysSeen[birthday] = True
    # Write to standard output the average number of people that must be sampled before a match,
    # as an int.
    stdio.writeln(count // trials)

Answer 1

在Python中，您可以

print(count // trials)

几乎所有数据结构都定义了__repr__()或__str()__方法。

由于count和trials应该是纯数字数据类型，因此print()应该可以解决问题

Answer 2

您的while循环有一个else，它将变成无限循环。选中此行以与if而不是while匹配：

    else:
        # Record the fact that we are seeing this birthday for the first time.
        birthdaysSeen[birthday] = True

此外，结尾处的打印文字应该是total // trials而不是count // trials

Answer 3

我建议使用print()代替stdio.writeln()

Answer 4

stdio.writeln不是内置的Python函数。使用print或从sys模块导入stdout并像这样写：

from sys import stdout

stdout.write(count // trials + "\n")

\n是换行符。 print自动添加换行符。 sys.stdout.write不会。

Python程序未提供输出

4 个答案: