Can someone enlighten me on the great disparity in speed?

Somewhat. Integer arithmetic is very close to being the pathological case. There are machine instructions expressly designed to do this stuff; very little high-level structure is required (unless you want to deal gracefully with adverse circumstances, such as an overflow). As a result, low-level languages are blazingly fast, because they cut out a lot of the normal operational overhead, which turns out to be the bulk of the runtime for a problem like this, precisely because the problem itself is such a simple one from the computer's perspective.

In case you hadn't noticed, you're looping several hundred million times. The "slowness" you're seeing in Perl is normal operational overhead, and under more typical circumstances you'd never notice it because it would get lost in the underflow. Put something more substantial than integer arithmetic inside that inner loop (in both C/C++ and Perl, the same thing) and see what happens. For example, inside the inner loop, write out a short message (maybe including the number you're on) to a logfile. Then compare.

{my$c;$ x=sub{++$c}}map{$ \.=$_->()}map{my$a=$_->[1];
sub{$a++ }}sort{_($a->[0 ])<=>_( $b->[0])}map{my@x=(&
$x( ),$ _) ;\ @x} split //, "rPcr t lhuJnhea eretk.as
o";print;sub _{ord(shift)*($=-++$^H)%(42-ord("\r"))};
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