Some tips about solving challenges at
I will not tell how to actually solve challenges,
but I do tell how to analyze different problems and failures.
These tips are based on my experience with CodeEval.
Failed with no time used
If Time and Memory columns have just "-" with no number,
then failure has nothing to do with your output
because solution was marked as failed before output was even checked.
Possible failure reasons include compilation failure or wrong return code.
Click on the View error link (or click revision number) and go see your output.
In case of compilation failure you should have error message there.
If there is no error message and output seems correct,
then it is possible that your program had wrong return code which automatically
marks solution failed. (Right return code is zero.)
Failed with some time used
If Time and Memory columns have some values,
then Failed means that you got zero score because
you did not output even a single correct output line.
Status Partially means that some output lines were correct, but not all.
Score is calculated from how many correct output lines you have,
compared to how many output lines challenge expects.
For example if challenge expects 20 lines of output and you get
19 lines correct then your score is 19 / 20 * 100 = 95.
Solved but no ranking points
If you get status Partially or Solved but Ranking points
is just "---",
then your solution used too much time (over 10 seconds) or memory (over 20 MB).
Note also that if you submit several solutions,
only last solution for each language gets ranking points.
Check you input and output
You can always see your input for easy challenges and
output for all challenges.
- Select Scores -> My Scores from top menu and wait for page to load.
- Find the challenge you want (e.g. search by challenge name) and click it.
- Click on the revision number of the revision you want.
(See image below).