Grader returns "W"

I just finished analysis mode on the problem Range Reconstruction (USACO), and all my code checks out all of the sample inputs. However, when I submit my code, the grader returns the message:

The grader for this problem says:

Your output (written to stdout):
-1 1 0

What does this mean? Am I doing something wrong? Thanks.

I have the same issue

k, I see what’s going on
remove the trailing whitespace/newline solved the problem.