I'd venture to say that a question like this would explicitly go against the Stack Exchange spirit of helping more people than just the original poster.
However, if you can word the question in a way that it is likely to help others, then it would probably be on topic. For example:
I'm trying to decode O AOLR QIXXAOMH; OY OD S DYSVL RCVJSMHR DOYR. I've figured out that there is a one-to-one letter correspondence, and that O and S correspond to one-letter words. How should I go about determining what words they represent?
I'm trying to solve this sudoku. There are two squares in the same row, and they can both be either [x] or [y]. What is this situation called, and how can it be solved?
These aren't the best examples, but you get the idea - try to word the question in a broad enough way that it will help others in the future.