I recently solved a practice problem called Chores making use of 1-indexed array. When I ran it on codeblocks it was giving the right answer but then I submitted and got a WA (even the custom invocation was giving wrong). I think that the judge used 0-indexed array by default.

This is the link to that submission: http://mirror.codeforces.com/contest/169/submission/18770974

Then I changed the code to 0-indexed and it passed. Is this a problem with Codeforces in general or is it a bug just this time?

This is the link to the AC answer: http://mirror.codeforces.com/contest/169/submission/18770997

I code in C++ FYI.

Thank you for replying!