Question

所以我正在通过Project Euler＃17工作，试图找到答案，而不是真正的目标是提高效率。然而，在阅读了我打印的每一个数字（我认为）后，我找不到正确答案正是100个字符的答案。所以我决定来找SO，当我在事故中使用Python 2.7在线编译时，我得到了截然不同的结果！我不确定为什么在Python 2.7中编译它会导致一个非常错误的答案，而在Python 3中它几乎没有。无论如何，这里是我在网上编译的两个地方：

正确答案，我的Python 3答案，我的Python 2.7答案： 21124,21224,1863

Python 3： http://ideone.com/ugfSV1

Python 2.7：我不知道如何分享它，因此您只需手动复制并粘贴以下代码http://www.compileonline.com/execute_python_online.php

这是我的算法：

import time

start = time.time()

singles = {0: "",
           1: "one",
           2: "two",
           3: "three",
           4: "four",
           5: "five",
           6: "six",
           7: "seven",
           8: "eight",
           9: "nine",
           10: "ten",
           11: "eleven",
           12: "twelve",
           13: "thirteen",
           14: "fourteen",
           15: "fifteen",
           16: "sixteen",
           17: "seventeen",
           18: "eighteen",
           19: "nineteen"}

tens = {2: "twenty",
        3: "thirty",
        4: "fourty",
        5: "fifty",
        6: "sixty",
        7: "seventy",
        8: "eighty",
        9: "ninety"}

hundred = "hundred"
count = 0

for num in range(1001):

    if len(str(num)) == 4:
        word = "onethousand"

    elif len(str(num)) == 3:
        first = singles[num // 100] + hundred

        if num % 100 == 0:
            first = singles[num // 100] + hundred
            second = ""

        elif num % 100 < 20:
            first += "and"
            second = singles[num % 100]

        elif num % 100 < 100:
            first += "and"
            second = tens[(num % 100) // 10]

        if isinstance(((num % 100) / 10), float) and (num % 100 > 20):
            third = singles[(num % 100) % 10]
        else:
            third = ""

        word = first + second + third

    elif len(str(num)) == 2:
        if num > 19:
            first = tens[num // 10]
            second = singles[num % 10]
            word = first + second
        else:
            word = singles[num]

    elif len(str(num)) == 1:
        word = singles[num]

    print(word)
    count += len(word)

print("The total number of letters in all words from 1 to 1000 is: {}".format(
    count))

print("Time: {}".format(time.time() - start))

Answer 1

isinstance(((num % 100) / 10), float)在Python 3上始终为true，在Python 2上始终为false（假设num为int）。有关此更改，请参阅PEP 238。

Answer 2

一些错误。

＆＃34; 40＆＃34;不是＆＃34;四十＆＃34;

＆＃34;一千＆＃34;不是＆＃34; onethousand＆＃34;

＆＃34; 21＆＃34;不是＆＃34;二十四＆＃34;你没有插入连字符的逻辑

＆＃34;一百＆＃34;不是＆＃34;一百个＆＃34;你的逻辑并没有用空格填充和

＆＃34;一百零一个＆＃34;不是＆＃34; onehundredandone＆＃34;再次，缺少插入空格的逻辑

＆＃34;二百一十一＆＃34;不是＆＃34;两百人＆＃34;缺少为200-999

插入和的逻辑

Project Euler＃17的意外结果（Python 3 vs Python 2.7）

2 个答案: