homework的参考答案

1. 来源一：

• hw0.
  https://blog.csdn.net/lala_623625/article/details/78842007
• hw1.
  https://samaelchen.github.io/2017/10/11/machine_learning_hw01/
  
• hw2:
  https://samaelchen.github.io/2017/12/26/machine_learning_hw02/
  
• hw3:
  https://samaelchen.github.io/2018/02/01/machine_learning_hw03/
• hw4:
  https://samaelchen.github.io/2018/02/12/machine_learning_hw04/

来源2：