Why does my code work fine on my machine but not on HackerRank??

If a lot of people have already solved a challenge, the odds are that the issue is in your code.

There could be a couple reasons for this:

• Your code doesn't match the expected output. The output produced by your code must exactly match the output expected by the test case, so something like a spelling error in your output will cause you to fail the challenge.
• You're using a different compiler. Check out our Environment page for up-to-date information on how we're compiling your code.
• Your code's behavior is unpredictable. If you're using C/C++, double check for uninitialized variables or invalid memory accesses, as they can cause unpredictable behavior. If you overrun an array or attempt to print the contents of an array cell that was never initialized, your output may look like it's correct but you'll fail the challenge (invisible garbage characters are the worst, we know).
• Ask for help. Each challenge has a Discussions tab where you can collaborate with fellow programmers who've attempted that challenge. When asking for help, be sure to provide detailed information that will enable others to understand what you're talking about.
• If you're really convinced that there is an issue with a test case, contact us directly with specific information about the challenge and test case number. Be sure to specifically state why you think it's not correct!