📅  最后修改于: 2022-03-11 14:59:08.027000             🧑  作者: Mango
A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, "ace" is a subsequence of "abcde" while "aec" is not).