摘要：
1 public class Solution { 2 public boolean exist(char[][] board, String word) { 3 if(!isValidBoard(board) || word == null || word.length() == 0) { 4 r 阅读全文
摘要：
1 public class Solution { 2 public String convert(String s, int numRows) { 3 // illegal parameters 4 if(s == null || s.length() == 0 || numRows <= 0) 阅读全文