$options{tests} = encode_json \@tests if @tests;
db->insert(problems => \%options);
db->insert(contest_problems => {problem => $id, contest => $contest}) if $contest;
$options{tests} = encode_json \@tests if @tests;
db->insert(problems => \%options);
db->insert(contest_problems => {problem => $id, contest => $contest}) if $contest;