| slovo | definícia |
brute force
(gcide) | Brute \Brute\, a. [F. brut, nasc., brute, fem., raw, rough,
rude, brutish, L. brutus stupid, irrational: cf. It. & Sp.
bruto.]
1. Not having sensation; senseless; inanimate; unconscious;
without intelligence or volition; as, the brute earth; the
brute powers of nature.
[1913 Webster]
2. Not possessing reason, irrational; unthinking; as, a brute
beast; the brute creation.
[1913 Webster]
A creature . . . not prone
And brute as other creatures, but endued
With sanctity of reason. --Milton.
[1913 Webster]
3. Of, pertaining to, or characteristic of, a brute beast.
Hence: Brutal; cruel; fierce; ferocious; savage; pitiless;
as, brute violence. --Macaulay.
[1913 Webster]
The influence of capital and mere brute labor.
--Playfair.
[1913 Webster]
4. Having the physical powers predominating over the mental;
coarse; unpolished; unintelligent.
[1913 Webster]
A great brute farmer from Liddesdale. --Sir W.
Scott.
[1913 Webster]
5. Rough; uncivilized; unfeeling. [R.]
[1913 Webster]
brute force, The application of predominantly physical
effort to achieve a goal that could be accomplished with
less effort if more carefully considered. Figuratively,
repetitive or strenuous application of an obvious or
simple tactic, as contrasted with a more clever stratagem
achieving the same goal with less effort; -- as, the first
prime numbers were discovered by the brute force
repetition of the Sieve of Eratosthenes.
[PJC] |
brute force
(foldoc) | brute force
A primitive programming style in which the
programmer relies on the computer's processing power instead
of using his own intelligence to simplify the problem, often
ignoring problems of scale and applying naive methods suited
to small problems directly to large ones. The term can also
be used in reference to programming style: brute-force
programs are written in a heavy-handed, tedious way, full of
repetition and devoid of any elegance or useful abstraction
(see also brute force and ignorance).
The canonical example of a brute-force algorithm is
associated with the "travelling salesman problem" (TSP), a
classical NP-hard problem:
Suppose a person is in, say, Boston, and wishes to drive to N
other cities. In what order should the cities be visited in
order to minimise the distance travelled?
The brute-force method is to simply generate all possible
routes and compare the distances; while guaranteed to work and
simple to implement, this algorithm is clearly very stupid in
that it considers even obviously absurd routes (like going
from Boston to Houston via San Francisco and New York, in that
order). For very small N it works well, but it rapidly
becomes absurdly inefficient when N increases (for N = 15,
there are already 1,307,674,368,000 possible routes to
consider, and for N = 1000 - well, see bignum). Sometimes,
unfortunately, there is no better general solution than brute
force. See also NP-complete.
A more simple-minded example of brute-force programming is
finding the smallest number in a large list by first using an
existing program to sort the list in ascending order, and then
picking the first number off the front.
Whether brute-force programming should actually be considered
stupid or not depends on the context; if the problem is not
terribly big, the extra CPU time spent on a brute-force
solution may cost less than the programmer time it would take
to develop a more "intelligent" algorithm. Additionally, a
more intelligent algorithm may imply more long-term complexity
cost and bug-chasing than are justified by the speed
improvement.
When applied to cryptography, it is usually known as {brute
force attack}.
Ken Thompson, co-inventor of Unix, is reported to have
uttered the epigram "When in doubt, use brute force". He
probably intended this as a ha ha only serious, but the
original Unix kernel's preference for simple, robust and
portable algorithms over brittle "smart" ones does seem to
have been a significant factor in the success of that
operating system. Like so many other tradeoffs in software
design, the choice between brute force and complex,
finely-tuned cleverness is often a difficult one that requires
both engineering savvy and delicate aesthetic judgment.
[Jargon File]
(1995-02-14)
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brute force
(jargon) | brute force
adj.
Describes a primitive programming style, one in which the programmer relies
on the computer's processing power instead of using his or her own
intelligence to simplify the problem, often ignoring problems of scale and
applying naive methods suited to small problems directly to large ones. The
term can also be used in reference to programming style: brute-force
programs are written in a heavyhanded, tedious way, full of repetition and
devoid of any elegance or useful abstraction (see also {brute force and
ignorance}).
The canonical example of a brute-force algorithm is associated with the
‘traveling salesman problem’ (TSP), a classical NP-hard problem: Suppose
a person is in, say, Boston, and wishes to drive to N other cities. In what
order should the cities be visited in order to minimize the distance
travelled? The brute-force method is to simply generate all possible routes
and compare the distances; while guaranteed to work and simple to
implement, this algorithm is clearly very stupid in that it considers even
obviously absurd routes (like going from Boston to Houston via San
Francisco and New York, in that order). For very small N it works well, but
it rapidly becomes absurdly inefficient when N increases (for N = 15, there
are already 1,307,674,368,000 possible routes to consider, and for N = 1000
— well, see bignum). Sometimes, unfortunately, there is no better general
solution than brute force. See also NP- and rubber-hose cryptanalysis.
A more simple-minded example of brute-force programming is finding the
smallest number in a large list by first using an existing program to sort
the list in ascending order, and then picking the first number off the
front.
Whether brute-force programming should actually be considered stupid or not
depends on the context; if the problem is not terribly big, the extra CPU
time spent on a brute-force solution may cost less than the programmer time
it would take to develop a more ‘intelligent’ algorithm. Additionally, a
more intelligent algorithm may imply more long-term complexity cost and
bug-chasing than are justified by the speed improvement.
Ken Thompson, co-inventor of Unix, is reported to have uttered the epigram
“When in doubt, use brute force”. He probably intended this as a {ha ha
only serious}, but the original Unix kernel's preference for simple,
robust, and portable algorithms over brittle ‘smart’ ones does seem to
have been a significant factor in the success of that OS. Like so many
other tradeoffs in software design, the choice between brute force and
complex, finely-tuned cleverness is often a difficult one that requires
both engineering savvy and delicate esthetic judgment.
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| | podobné slovo | definícia |
brute force and ignorance
(czen) | Brute Force and Ignorance,BFI[zkr.] |
brute force and massive ignorance
(czen) | Brute Force and Massive Ignorance,BFMI[zkr.] |
brute force and ignorance
(foldoc) | brute force and ignorance
BFI
(BFI) A popular design technique at many software
houses - brute force coding unrelieved by any knowledge of
how problems have been previously solved in elegant ways.
Dogmatic adherence to design methods tends to encourage this
sort of thing. Characteristic of early larval stage
programming; unfortunately, many never outgrow it.
Also encountered in the variants BFMI - brute force and
massive ignorance, and BFBI - brute force and bloody
ignorance.
"Gak, they used a bubble sort! That's strictly BFI."
Compare bogosity.
[Jargon File]
(1996-06-12)
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brute force attack
(foldoc) | brute force attack
A method of breaking a cipher (that is, to
decrypt a specific encrypted text) by trying every possible
key. The quicker the brute force attack, the weaker the
cipher. Feasibility of brute force attack depends on the key
length of the cipher, and on the amount of computational power
available to the attacker. Brute force attack is impossible
against the ciphers with variable-size key, such as a
one-time pad cipher.
{Breaking ciphers with many workstations
(http://distributed.net/projects.html.en)}.
(2000-01-16)
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brute force and ignorance
(jargon) | brute force and ignorance
n.
A popular design technique at many software houses — brute force coding
unrelieved by any knowledge of how problems have been previously solved in
elegant ways. Dogmatic adherence to design methodologies tends to encourage
this sort of thing. Characteristic of early larval stage programming;
unfortunately, many never outgrow it. Often abbreviated BFI: “Gak, they
used a bubble sort! That's strictly from BFI.” Compare bogosity. A very
similar usage is said to be mainstream in Great Britain.
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