In the math cram school, the teacher gave us all the questions in the textbook and said, is this effective? Why not buy a complete solution yourself ~
Of course, the teacher's explanation is better, because we need to learn not only this problem, but the idea of doing it, and the teacher's guidance is very important for our idea of doing it. My favorite physics teacher in high school took us step by step to find a solution. Personally, I feel that if I look at the topic, I can easily fall into one-sided memory, and only by understanding can I learn better.