Question on learning to program.

I have stated picking up on programming the last few weeks. I took a class to help me build the fundamentals. My teacher just gives us an assignment and then runs it works he gives a perfect grade. I wish that he would take the time to look at our code and tell us how we can more effectively do the task with less calculations. Should I be focusing on doing things more efficiently at this point? Or should I try to grasp the programming language and how it works and then re-adjust and worry about run time later on?

I recently created a binary converter that did the calculations, set the digits in an array, and the output the array contents backwards. The program works, but is there a much better way to do this?

Thanks!

My suggestion is that you should put major efforts on learning java core classes. Once you know them, you will be able to write programs even more efficiently. Of course, if you can see an obvious optimization or have some free time, try to optimize or think of optimization, but that should not harm learning the language basics.