Discarding my moderator hat here for a real post:
I disagree with the fact that this is "guessing". This site actually more realistically matches what happens in the "real world". When I am given a task at work, I need to ask questions and determine the requirements before I start to write code. After I'm finished writing my code I need to test it on a wide variety of situations to verify that it works. If I release it to the public and it doesn't work on some input that the user puts into it, it puts the whole business in jeopardy.
Imagine now that clicking "Submit" is equivalent to releasing your code to the public. Does it make more sense now?
This website is not a "coding" website. It is a problem solving website. That is why there are so many languages available. Code is just a tool to implement the solution to a problem.
Moderator Hat Back On:
If you are getting a wrong answer on this website it is more likely because you have handled the constraints of the input incorrectly and not considered possible test cases than the fact that the judge is not correct. If a judge is not correct, there will be many many comments mentioning that and people will not be getting accepted on it. If people are getting accepted on it, then the issue is with your solution. I suggest posting for help on the forum in the Problemset section, someone will likely help you.