The Python Challenge(5)

问题链接

问题链接如下：

http://www.pythonchallenge.com/pc/def/linkedlist.php

答案链接

答案链接如下：

http://www.pythonchallenge.com/pc/def/peak.html

解题思路

根据页面源码提示：

<!-- urllib may help. DON'T TRY ALL NOTHINGS, since it will never 
end. 400 times is more than enough. -->

再点击页面图片显示：

and the next nothing is 44827

可知是需要一直跳转，则有如下代码：

from urllib import request
import re

url = 'http://www.pythonchallenge.com/pc/def/linkedlist.php?nothing='
id = '12345'
while True:
    response = request.urlopen(url+id)
    content = str(response.read(), 'utf-8')
    print(content)
    ret = re.findall('and the next nothing is (\d+)', content)
    if len(ret) == 0:
        print(url+id)
        break
    id = ret[0]

显示到如下内容，然后停止：

and the next nothing is 16044
Yes. Divide by two and keep going.

则把代码中的初始ID替换为8022，再次执行有如下结果：

and the next nothing is 66831
peak.html

则最终URL应当为：http://www.pythonchallenge.com/pc/def/peak.html。