I have one suggestion. When learning some new data structure or algorithm, do not blindly follow only one source. Always Google the topic, and you will get various resources. This has two benefits.
Out of all the sources you find, many may have better explanations or more elegant code than your original source.
When you discover these new websites, they will have have other articles on related topics which you may not have heard of before. Additionally you will know where to look for when you want to learn some other thing later.