摘要：
Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return fa 阅读全文
摘要：
Write a function that takes a string as input and reverse only the vowels of a string. Example 1:Given s = "hello", return "holle". Example 2:Given s 阅读全文
摘要：
Write a function that takes a string as input and returns the string reversed. Example:Given s = "hello", return "olleh". 个人博客：http://www.cnblogs.com/ 阅读全文