"Johnson Lau" schreef:
> I need to compare two binary numbers and need perl to return the
> number of matching bits.
>
> For example:
>
> $aaa = "10111100";
> $bbb = "00101100";
>
> In this case, the number of matching bits is 6.
perl -Mstrict -Mwarnings -le'
my $b1 = "10111100";
my $b2 = "00101100";
$b2 =~ tr/01/10/;
my $n = ($b1 & $b2) =~ tr/0/0/;
print $n;
'
6
To derive the length, a prepared hash (with 256 keys) will be faster.
perl -Mstrict -Mwarnings -le'
my $b1 = oct "0b" . "10111100";
my $b2 = oct "0b" . "00101100";
my $n = sprintf("%08b", $b1 ^ $b2) =~ tr/0/0/;
print $n;
'
To derive the length, a prepared array (with 256 elements) is much
faster.
--
Affijn, Ruud
"Gewoon is een tijger."
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