摘要： Given an integer, convert it to a roman numeral.Input is guaranteed to be within the range from 1 to 3999.将不同罗马字符和对应的数字做成字典，然后将依次转化。时间：55ms代码如下：class ... 阅读全文

摘要： Givennnon-negative integersa1,a2, ...,an, where each represents a point at coordinate (i,ai).nvertical lines are drawn such that the two endpoints of ... 阅读全文

摘要： Implement regular expression matching with support for'.'and'*'.'.' Matches any single character.'*' Matches zero or more of the preceding element.The... 阅读全文

摘要： Determine whether an integer is a palindrome. Do this without extra space.看到题目第一想法是将数字倒过来相减，看是否为0，但是会超时。原因是大部分可能并不是，所以循环中间就退出循环了。目前这个程序是按最左位与最右位逐次比较。时... 阅读全文

摘要： Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, please do not see below and ... 阅读全文

摘要： Reverse digits of an integer.Example1:x = 123, return 321Example2:x = -123, return -321题目很简单，先判断数字的正负，再按位倒置数字就可以了。不过要考虑int的上限。时间：16ms代码如下：class Soluti... 阅读全文

摘要： 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 font fo... 阅读全文

摘要： Given a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there exists one unique longest pa... 阅读全文

摘要： There are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity should be ... 阅读全文

摘要： 今天清明，再补一篇Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating l... 阅读全文