Lazy DFAs (2010) are a clever optimization to mitigate the O(2^m) blowup of DFA construction, by only constructing the states that you actually visit. lazy DFAs reduce the theoretical automata construction time to either O(2^m) or O(n), whichever is lower. you could argue that it’s theoretically no longer linear time, since you could have a regex that creates a new state for every character in the input, but in practice you will keep revisiting the same states. for all intents and purposes it behaves more like O(n) with some initial wind-up time. the main downside of lazy DFAs is that they are more complex to implement, and you have to ship a compiler as part of your regex algorithm. i want to highlight Rust regex and RE2 as excellent implementations of this approach, which you can also see in the benchmarks.
Remarks on Infra-Modules
。爱思助手下载最新版本对此有专业解读
德国将农民纳入统一养老保险体系,按“农业经营者”与“农业从业者”分类设定缴费标准及待遇水平,对从事农业生产满15年的农民,退休后待遇不低于城镇职工养老金的60%。
推进宜居宜业和美乡村建设。学习运用“千万工程”经验,分类有序、片区化推进乡村振兴,深入实施乡村建设行动,逐步提高农村基础设施完备度、公共服务便利度、人居环境舒适度。创造乡村优质生活空间。发展县域富民产业。加强和改进乡村治理。
Follow topics & set alerts with myFT