这里要做的全部工作是匹配数字、运算符和换行。

All this does is match Numbers, operators, and newlines.

youdao

原先是简单的使用取模运算符（%）的实现，它非常低效，它自己检查从 2 到目标数的每个数字，确定是否是因子。

The original naive implementation used the modulus (%) operator, which is wildly inefficient, to check every number from 2 up to the target number itself to determine if it is a factor.

youdao

查询无效：确保括号完整，自定义查询只包含有效标准数字以及布尔型运算符and、OR和NOT。

Invalid query: make sure parenthesis are balanced and the custom query consists only of valid criteria Numbers and the Boolean operators and, or, and NOT.

youdao