38 lines
811 B
Perl
38 lines
811 B
Perl
use strict;
|
|
use feature 'say';
|
|
use POSIX qw(floor);
|
|
use ntheory qw/fromdigits todigits/;
|
|
|
|
sub encode {
|
|
my($n, $b) = @_;
|
|
my @out;
|
|
my $r = 0;
|
|
|
|
while ($n) {
|
|
$r = $n % $b;
|
|
$n = floor $n/$b;
|
|
$n += 1, $r -= $b if $r < 0;
|
|
push @out, todigits($r, -$b) || 0;
|
|
}
|
|
join '', reverse @out;
|
|
}
|
|
|
|
sub decode {
|
|
my($s, $b) = @_;
|
|
my $total = 0;
|
|
my $i = 0;
|
|
for my $c (reverse split '', $s) {
|
|
$total += (fromdigits($c, -$b) * $b**$i);
|
|
$i++;
|
|
}
|
|
$total
|
|
}
|
|
|
|
say ' 10 in base -2: ', encode(10, -2);
|
|
say ' 15 in base -10: ', encode(15, -10);
|
|
say '146 in base -3: ', encode(146, -3);
|
|
say '';
|
|
say '11110 from base -2: ', decode("11110", -2);
|
|
say '21102 from base -3: ', decode("21102", -3);
|
|
say ' 195 from base -10: ', decode("195", -10);
|