my ($h_run, $t_run, $longest_run) = (0,0,0);
while () {
    if (int rand 2) { # had silly use of flip-flop -- thanks, tlm
        ++$h_run;
        $longest_run = $h_run if $h_run > $longest_run;
        $t_run = 0;
    }
    else {
        #similarly
    }
}