$PAT = '$X =~ s{^(.*?)Resolved (\d+) problems out of (\d+) picked(.*?)$}{ (($3-$2)/$3>.5) ? 1 : 0 }se';

##</code><code>##

$X = "Line1\nLine2Resolved 200 problems out of 5000 picked\nLine4\nLine5";