Polish notation

Question

Why doesn’t it work ?
https://code.sololearn.com/c72AJsxkJ1gV/?ref=app

Answer 1

Leaving aside that the program is not freeing borrowed memory, that it's not cheking for any kind of erroneous input, the warnings, and the fact it uses ALG notation (not Polish);
as long as you don't put spaces in the input it should work fine

Can you show us an example where it doesn't work?

Answer 2

I improve it. Now it works
https://code.sololearn.com/cLA1gD7W5jj8/?ref=app