James Pan

原题网址：https://leetcode.com/problems/reverse-words-in-a-string-ii/Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input stri

原题网址：https://leetcode.com/problems/length-of-last-word/Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.

原题网址：https://leetcode.com/problems/valid-number/Validate if a given string is numeric.Some examples:"0" => true" 0.1 " => true"abc" => false"1 a" => false"2e10" => trueNote:

原题网址：https://leetcode.com/problems/restore-ip-addresses/Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example:Given "2552551

原题网址：https://leetcode.com/problems/simplify-path/Given an absolute path for a file (Unix-style), simplify it.For example,path = "/home/", => "/home"path = "/a/./b/../../c/", => "/c"

原题网址：https://leetcode.com/problems/string-to-integer-atoi/Implement atoi to convert a string to an integer.Hint: Carefully consider all possible input cases. If you want a challenge, please

原题网址：https://leetcode.com/problems/serialize-and-deserialize-binary-tree/Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in

原题网址：https://leetcode.com/problems/compare-version-numbers/Compare two version numbers version1 and version2.If version1 > version2 return 1, if version1 version2 return -1, otherwise return 0

原题网址：https://leetcode.com/problems/excel-sheet-column-number/Related to question Excel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column num

原题网址：https://leetcode.com/problems/validate-ip-address/方法：扫描检查，代码写得比较丑陋，暂时凑合着。public class Solution { private static final String NEITHER = "Neither"; private static final String IPV4 = "I