You can vote on other Codewarrior's solutions to help uncover the best ones. There are 2 choices for voting:
Best Practices
Best practices are for solutions that you think are a good combination of being maintainable and efficient. They may not be the fastest solution - if the fastest solution involves overly optimizing the code in a way that becomes hard to read.
Clever
Clever votes are for solutions that you feel like are notable in some way, but not something you would expect to see in production code.
求二进制数中1的个数：
http://15838341661-139-com.iteye.com/blog/1642525