Select Code to Download

#!/usr/bin/perl -w
use Benchmark;
...
      keys %hash;
  }
});

Benchmark: timing 100 iterations of a, b...
         a: 274 wallclock secs (272.26 usr +  0.22 sys = 272.48 CPU)
         b: 366 wallclock secs (359.06 usr +  0.52 sys = 359.58 CPU)