also think about the behavior question on the banner of the page, which is more important in some cases. (show hint gives the answer). The Q&A comes from one excellent post here. //salute.
j*x
9 楼
Sort of difficult to begin, but really simple questions.
【在 d***8 的大作中提到】 : A long string text, given some characters, find the shortest : substring covering all given characters.