julycoding/The-Art-Of-Programming-by-July — pull request #83 by blackball (2014-01-02 03:14:30+00:00)
Title: Update 02.0.md

之前的bit hack有误，0x3f需要改为0x1f。同时考虑到bit version属于奇淫巧技，容易误导人，可读性也不强。所以加入了histogram version。