While solving I find some problems which I couldn't solve after hard trying with them ; so for such problems I'm confused ..

which is better in that case ?

A- Push the problem to my to-do list , keep going solving other problems and return back to solve it later after a while . Maybe after solving other problems , and after solving it read the editorial and figure out what went wrong with me that made me unable to solve it the first time . If after I return to solve it and couldn't solve it again : repeat A .

B- After I'm completely done with the problem and I'm no longer making any progress with it , I start read the editorial , find what's it about and figure out what went wrong with me that made me unable to solve it .