摘要：
题目描述 Given a string s, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrome you 阅读全文
摘要：
题目描述 Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially 阅读全文
摘要：
题目描述 Design a data structure that supports the following two operations: search(word) can search a literal word or a regular expression string contain 阅读全文