正则表达式中的模运算符 [英] Modulo operator in a regular expression

问题描述

我正在尝试编写一个正则表达式来接受任何二进制字符串，唯一的标准是 0 的数量不是 3 的因数([0 的数量] % 3 != 0).如何实现?

I am attempting to write a regular expression to accept any binary strings with the only criteria being that the number of 0s is not a factor of 3 ([number of 0s] % 3 != 0). How can this be achieved?

推荐答案

如果您的正则表达式风格支持 递归模式，你可以使用这个:

If your regex flavour supports recursive pattern, you could use this:

^(1*01*)(?1)?(?:(?1)(?1)(?1))*1*$

如果不是，则将所有 (?1) 替换为 (1*01*)

If it doesn't, replace all (?1) by (1*01*)

说明:

^               : begining of string
  (             : start group 1
    1*01*       : that contains 0 or more 1, one 0 and 0 or more 1
  )             : end group
                    At this time, we have one 0
  (?1)?         : Same pattern as group 1 (ie. 1*01*), optional
                    we have now one or two 0
  (?:           : non capture group
    (?1)(?1)(?1): pattern 1 repeated 3 times
  )*            : 0 or more times
                    we have one or two 0 followed by three 0, 
                    so the number of zeros modulo 3 != 0
  1*            : 0 or more 1
$               : end of string.

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