摘要：
题意： The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed f 阅读全文
摘要：
题意： Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique lo 阅读全文