from this list, the two reasonable options are either DFAs (best choice if you can compile ahead of time) or lazy DFAs (great for both random user input and large regexes). NFAs are just not competitive in reality, and backtracking engines are a security nightmare.
And… the answer is “none”.。关于这个话题，WPS下载最新地址提供了深入分析
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Any one of these signals on its own would be suspicious. Together, they paint a pretty clear picture.