bug ???

2 same codes solving 2 different tasks ...
hmmm ... bug ???
z-query: http://z-trening.com/submit.php?subm_stat=1&submit=7100170057

mecho: http://z-trening.com/submit.php?submit=7100170056&subm_stat=1

that solution is for task mecho, but why it is graded for z-query and got AC ???
or is there some problem with overwriting codes ?

Several months ago the same happened. Please moderators, regrade tasks z-query, BubbleString ...

again...