摘要：
Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Exampl 阅读全文
摘要：
Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. For example, two is written as II in Roman numeral, just two one's 阅读全文
摘要：
Given a 32-bit signed integer, reverse digits of an integer. Example 1: Example 2: Example 3: Note:Assume we are dealing with an environment which cou 阅读全文