完成的代码在hw4.ipynb中，代码实现的具体内容也在该文件中了。

以下为斯坦福课程提供的环境配置教程。

We will use Conda to obtain a standard installation of Python and related useful packages. If you aren't already using it, please install it using the platform-specific instructions provided on the Conda installation page.

We have provided an environment file for this assignment. To create a new environment with the correct packages, run

 conda env create -f environment.yml

This will create a new environment named cs276-pa1. You can activate it by running

 conda activate cs276-pa1

Once you are done working on the assignment, you can deactivate it by running

 conda deactivate

If you’ve got conda v4.4+, you should use conda activate cs276-pa1 and similarly conda deactivate

We'll be using a Jupyter notebook to do our assignment. You can start a new session with

  jupyter notebook

This will start a local server which you can then connect with using a local browser.