Efficient trial-and-error should help you acquire a good understanding of the solution.
When your program finally works, are you really sure why? If not, you might be doing it wrong.
You might want to google "test driven development". Basically, it's a programming discipline which heavily relies on shortening your feedback loops (i.e reduce the time between the moment you make an error and the moment you detect it). While it certainly is controversial, it can be seen as a serious formalization of "trial and error".
It depends.
Efficient trial-and-error should help you acquire a good understanding of the solution. When your program finally works, are you really sure why? If not, you might be doing it wrong.
You might want to google "test driven development". Basically, it's a programming discipline which heavily relies on shortening your feedback loops (i.e reduce the time between the moment you make an error and the moment you detect it). While it certainly is controversial, it can be seen as a serious formalization of "trial and error".