摘要：Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 字符串的是从左边开始的 res,p 是元组 阅读全文

摘要：Determine whether an integer is a palindrome（回文）. Do this without extra space. 阅读全文

摘要：Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Note:The input is assumed to be a 32-bit signed integer. Yo 阅读全文

摘要：Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have ex 阅读全文