http://www.ppvke.com/Blog/archives/44035(人人都是数据加)
https://www.cnblogs.com/ljy2013/p/6890408.html
http://blog.csdn.net/szlcw1/article/details/52259668
http://www.ppvke.com/Blog/archives/38175
http://www.ppvke.com/Blog/archives/50817
http://www.ppvke.com/Blog/archives/47360
http://www.ppvke.com/Blog/?s=面试题
https://www.cnblogs.com/MrLJC/p/4099404.html(决策树)