WC -Sx- Jones wrote:
> WC -Sx- Jones wrote:
> > What is happening here -
> > while(1) {
> > (++$count) ? $count += $count-- : $count += $count++;
> >
>
> :) May I ask a different way?
>
> #! /usr/bin/perl
> use strict;
> use warnings;
>
> my $count;
> my $str;
>
> while(1) {
> (++$count) ? $count += $count--
> : $count += $count++;
>
> $str = unpack("B32", pack("N", $count));
> print "$count \tis binary $str\n";
> exit if $count > 60_000;
> sleep 1;
> }
>
> __END__
> -Sx-
>
> PS - I am admit that I am likely in the middle of
> a nervous break-down LOL :)
>
> BTW - Joseph was correct about the side-effects issue. :)
> No one seemed to address the other data formats...
That is pretty much how I got there. Not that I would have to unpcak those
numbers--they're pretty much engreained onmy memory ever since an instructor
gave us the prefect number problem as an assignment. Definitely increased my
admiration for Euclid, who did not have the binary p[aradigm to work with.
To elaborate a little:
Greetings! E:\d_drive\perlStuff>perl -w
#!perl -w
use strict;
use warnings;
my $count;
while(1) {
if (++$count) { # on second round: $count == ($oringinal * 4 -
1) + 1 == $oringinal * 4
# $oringinal = $count == 1
$count += $count; # $count == $oringinal * 2
$count--; # $count == ($oringinal * 2) - 1
my $alternative_yes = $count; #dead code
$count += $count; # $count == (($oringinal * 2) - 1) * 2 == (($oringinal
* 2) * 2) - (1 * 2) == ($oringinal * 4) - 2
$count++; # $count == (($oringinal * 4) - 2) + 1 == $oringinal
* 4 - 1
my $alternative_no = $count; #dead code
} else {
die "The impossible has happened! $!";
}
print "$count\n"; exit if $count > 60_000;
sleep 1;
}
^Z
3
15
63
So the upshot is that the function essentially quadruples the base value for the
loop on each iteration, but prints a value one less than the base value.
The values above could be clearly exzpressed as
4 -1
16 -1
64 -1
256 -1
or
4 ** 1 - 1
4 ** 2 - 1
4 ** 3 -1
..with a bit of sleight of hand thrown in for spice.
Joseph
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