Select Code to Download

Benchmark: timing 2000 iterations of Krambambuli, blazar...
Krambambuli:  4 wallclock secs ( 3.28 usr +  0.01 sys =  3.29 CPU) @ 6
+07.90/s (n=2000)
    blazar:  1 wallclock secs ( 0.80 usr +  0.00 sys =  0.80 CPU) @ 25
+00.00/s (n=2000)

use strict;
...
    $count{$_} == 1 and delete $count{$_} for keys %count;
    \%count;
}