Hello everyone, I am a beginner.

[wdk5233]

I feel confused in the smart pointer and recursive.
I was watching C++ Primer Plus.
Can give some advice for the beginners.

[cire]

Can give some advice for the beginners.

Post in the correct forum. Use code tags when appropriate. Include minimal, compilable code for any problem you have a question about where possible.

I feel confused in the smart pointer and recursive.

Be much more specific when asking for help. This is vague to the point of uselessness.

I was watching C++ Primer Plus.

I think purchasing C++ Primer Plus is probably not a great investment. On the other hand, if you're already using it, I'm sure it's serviceable.