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GeneralRe: Performance problem with my FindOneOf function Pin
Ivan Ivanov 8323-Jun-09 4:17
Ivan Ivanov 8323-Jun-09 4:17 
GeneralRe: Performance problem with my FindOneOf function Pin
Ivan Ivanov 8324-Jun-09 1:11
Ivan Ivanov 8324-Jun-09 1:11 
AnswerRe: Performance problem with my FindOneOf function Pin
Skippums22-Jun-09 9:02
Skippums22-Jun-09 9:02 
GeneralRe: Performance problem with my FindOneOf function Pin
Stuart Dootson22-Jun-09 9:34
professionalStuart Dootson22-Jun-09 9:34 
GeneralRe: Performance problem with my FindOneOf function Pin
Ivan Ivanov 8322-Jun-09 11:28
Ivan Ivanov 8322-Jun-09 11:28 
AnswerRe: Performance problem with my FindOneOf function Pin
Roger Stoltz22-Jun-09 9:22
Roger Stoltz22-Jun-09 9:22 
GeneralRe: Performance problem with my FindOneOf function Pin
Ivan Ivanov 8322-Jun-09 10:59
Ivan Ivanov 8322-Jun-09 10:59 
GeneralRe: Performance problem with my FindOneOf function Pin
Roger Stoltz22-Jun-09 21:39
Roger Stoltz22-Jun-09 21:39 
Member 4399131 wrote:
You actually bother yourself to write and test this code to help me


Well, yesterday must have been one of my good days and I guess the Fairy of Kindness must have hit my forehead with her wand since I got a bump... Wink | ;)

Seriously, the algorithm is not very good in my opinion. Given certain preconditions it is actually faster than CString::FindOneOf(), but it can also be awfully slow. The whole idea with the algorithm I provided is to find at least one bit that are common for all characters to be searched for that is not very common in the string to be searched. In practice this means that searching for a digit (ASCII 0x30 - 0x39) in a string that only contains letters (ASCII >0x41) is quite fast, but searching for a 'b' in a string with small letters will be rather slow.

My point was that an algorithm can be optimized for certain preconditions and may prove faster than a generic one if those preconditions are satisfied, but may be much slower than the generic one if they are not satisfied.
That's why I think Stuart's advice is the best one, i.e. to go with the C runtime implementation. It is likely implemented to give the best overall performance with an algorithm far better than mine.


"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown


GeneralRe: Performance problem with my FindOneOf function [modified] Pin
Ivan Ivanov 8324-Jun-09 1:45
Ivan Ivanov 8324-Jun-09 1:45 
GeneralRe: Performance problem with my FindOneOf function Pin
Roger Stoltz24-Jun-09 4:16
Roger Stoltz24-Jun-09 4:16 
GeneralRe: Performance problem with my FindOneOf function [modified] Pin
Ivan Ivanov 8325-Jun-09 1:25
Ivan Ivanov 8325-Jun-09 1:25 
QuestionXMLHTTP post failed with status code 415 Pin
Ash_VCPP22-Jun-09 3:47
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KarstenK22-Jun-09 4:15
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QuestionTimer on Statusbar Pin
susanne122-Jun-09 3:10
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AnswerRe: Timer on Statusbar Pin
Rajesh R Subramanian22-Jun-09 3:25
professionalRajesh R Subramanian22-Jun-09 3:25 
AnswerRe: Timer on Statusbar Pin
David Crow22-Jun-09 4:05
David Crow22-Jun-09 4:05 
QuestionHow to access element in Multiset by index Pin
alikalik22-Jun-09 3:05
alikalik22-Jun-09 3:05 
AnswerRe: How to access element in Multiset by index Pin
Chris Losinger22-Jun-09 3:13
professionalChris Losinger22-Jun-09 3:13 
GeneralRe: How to access element in Multiset by index Pin
alikalik22-Jun-09 3:30
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AnswerRe: How to access element in Multiset by index Pin
Sarath C22-Jun-09 3:20
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Questionsplit wavefiles programetically Pin
N Vamshi Krishna22-Jun-09 3:04
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AnswerRe: split wavefiles programetically Pin
Rozis23-Jun-09 6:42
Rozis23-Jun-09 6:42 
QuestionPlease clarify my doubt.... Pin
Rakesh522-Jun-09 2:25
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AnswerRe: Please clarify my doubt.... Pin
Stuart Dootson22-Jun-09 2:42
professionalStuart Dootson22-Jun-09 2:42 
QuestionAPI for changing Language for non-Unicode Programs???? Pin
Super Hornet22-Jun-09 1:39
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