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/