Subword Embedding

English Version pytorch
1

https://d2l.ai/chapter_natural-language-processing-pretraining/subword-embedding.html

2

My solutions to the exs: 15.6

3

a couple of questions:
a. in fastText, there are some specified lengths for subwords. does it mean that there are some different types of subwords set in vocab?
b. so this Subword embedding can not be used in asian languages, eg. Chinese , Japanese?