This is way over my head, but as a proof of concept, I tried to use Bit::Vector to compare the needle and haystack as strings. Probably not very efficient for the large sets you're talking about.

#!perl
use strict;
use warnings;

use Bit::Vector;

# 101001
my $nedInHay    = Bit::Vector->new_Dec(6, 41);
# 101000
my $nedNOTInHay = Bit::Vector->new_Dec(6, 40);
# 100101001001000011111010
my $hay = Bit::Vector->new_Dec(24, 9736442);

print $nedInHay->to_Bin;
if ((my $idx = index ($hay->to_Bin, $nedInHay->to_Bin )) != -1) {
    print " Found.  Starts at position - $idx\n"
}

print $nedNOTInHay->to_Bin;
if (my $idx = index ($hay->to_Bin, $nedNOTInHay->to_Bin ) != -1) {
    print " Found.  Starts at position - $idx\n"
}
print "\n"

[download]

... and run ...

VinsWorldcom@C:\Users\VinsWorldcom\tmp> test.pl
101001 Found.  Starts at position - 3
101000

[download]

In reply to Re: [OT] The interesting problem of comparing bit-strings. by VinsWorldcom
in thread [OT] The interesting problem of comparing bit-strings. by BrowserUk

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