how plagiarism works?

if i solve a question along with my friend in long challenge and there might be some similarities in our code will that count as plagiarism?

Long challenge is an individual contest, not supposed to be done in groups.
and even if it is done so, only one from the group is supposed to submit the solution.
Recommendation : contact admin describing the matter as soon as possible

how do i contact the admin?

try sending mail to and