1-10, 500x: 2 secs ( 1.13 usr 0.00 sys = 1.13 cpu) (printing) 1-10, 500x: 1 secs ( 0.48 usr 0.00 sys = 0.48 cpu) (not printing) 1-35m 10x: 26 secs (26.53 usr 0.00 sys = 26.53 cpu) (printing) 1-35, 10x: 15 secs (15.05 usr 0.00 sys = 15.05 cpu) (not printing) #### $x = 1; for(1..10){ $x =~ s/((.)\2*)/length($1).$2/ge; #print "@{[split//,$x]}\n"; }