Using it to count set bits in the whole bytes before your position and then, if necessary, those bits in the partial byte up to but not including it via a mask might be viable.
Yes. That works and is the same scheme questor came up with (rather more compactly:) in Re: Efficient bit counting with a twist..
But the best answer is the one AnomalousMonk pointed out in Re: Efficient bit counting with a twist..
Ie. To recognise that the unpack template '%32b*' is not a indivisible token saying 'count the bits', but actually contains 3 parts:
- %32 accumulate a 32-bit count ...
- b of the binary bits set ...
- * for all the bits in the string.
And that by simply interpolating $p into the template, in place of *, it counts the set bits within the first $p bits of the string.
Perl had the problem solved; I just didn't recognise it :) (Hence my: D'oh! D'oh! D'oh!..... moment. :)
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||