摘要： ``` public int GetUglyNumber_Solution(int index) { if (index 阅读全文

摘要： from: http://stackoverflow.com/a/3343829/5032462 在stackoverflow上看到的一篇回答，老外真是太professional了，mark一下。最后的summary值得看一下。 The Java API docs say the following 阅读全文

摘要： A reversible prime in any number system is a prime whose "reverse" in that number system is also a prime. For example in the decimal system 73 is a re 阅读全文

摘要： 1011. World Cup Betting (20) With the 2010 FIFA World Cup running, football fans the world over were becoming increasingly excited as the best players 阅读全文

摘要： This time, you are supposed to find A*B where A and B are two polynomials. Input Specification: Each input file contains one test case. Each case occu 阅读全文

摘要： The highest building in our city has only one elevator. A request list is made up with N positive numbers. The numbers denote at which floors the elev 阅读全文

摘要： A family hierarchy is usually presented by a pedigree tree. Your job is to count those family members who have no child. Input Each input file contain 阅读全文

摘要： Arrays.asList()返回一个实现了List接口的类，但是不支持add,remove等改变尺寸的操作。 Arrays.asList源码如下 这里有一个大坑，我开始没仔细看，以为返回的就是java.util.ArrayList，可实际上此ArrayList是Arrays里面的私有静态内部类，代 阅读全文

摘要： Given a non-negative integer N, your task is to compute the sum of all the digits of N, and output every digit of the sum in English. Input Specificat 阅读全文

摘要： At the beginning of every day, the first person who signs in the computer room will unlock the door, and the last one who signs out will lock the door 阅读全文