摘要：
Return the lexicographically smallest subsequence of text that contains all the distinct characters of text exactly once. Example 1: Input: "cdadabcc" 阅读全文
摘要：
Given many words, words[i] has weight i. Design a class WordFilter that supports one function, WordFilter.f(String prefix, String suffix). It will ret 阅读全文
摘要：
Given a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks. Tasks coul 阅读全文