>>>>>Thanks to all (Dragan, Marcia and Tore). I wonder which solution is the fastest?
>>>>>
>>>>>Since you have all the code, why don't you test all the solutions and let us know?
>>>>
>>>>(Edit: This reply is for Yossi)
>>>>
>>>>I think Dranag's solution is the fastest and optimal, because analyze the string only once and using the minimal instruction set.
>>>>
>>>Imagine tcBig 650KB long with 10000 "A": the check will be done 10000 times,
>>>If the "A" is at the end of the resulting string, will take longer ;-)))
>>
>>You are right, and I didn't saw Marcia's algorithm that is excelent!
>>
>>This is the testing results of the 3 algorithms in my PC with a 50000 chars string:
>>
>>- Dragan: 52.5 secs and maintain the original order
>>- Tore: 30.9 secs and doesn't maintain original order (order is alphabetical because SQL)
>>- Marcia: 1.4 secs and maintain the original order => WINNER!
>>
>>Congrats Marcia! :D
>
>hmmm, Is it too late to enter the compiteition?
>
>

FUNCTION NonDupe(cString)
>LOCAL cNewStr 
> 
>cNewStr =""
>DO WHILE LEN(cString) > 0
>	cNewStr = cNewStr + LEFT(cString,1)
>	cString = STRTRAN(cString, LEFT(cString,1))
>ENDDO
>RETURN cNewStr
>ENDFUNC

>
>Which is shorter and faster than Marcia's alghorithm by 40% in my testing
>
>But all are nothing compared when you've got some C++ code working for you.
>The FoxTools.fll contains a function REDUCE() which is extremely fast on eliminating characters from a string.
>It has been written to reduce spaces but has a different role for other characters. It will remove them and replace with spaces.
>
>The following alghorith does not not work for detecting the space as a separate character, but if you're only concerned with non-space characters the following is about a 100 times faster than Marcia's routine.
>
>
>

FUNCTION NonDupe3(cString)
>LOCAL cNewStr 
> 
>cNewStr =""
>
>DO WHILE LEN(cString) > 0
>	cNewStr = cNewStr + LEFT(cString,1)
>	cString = LTRIM(REDUCE(cString, LEFT(cString,1)))
>ENDDO
>RETURN cNewStr
>ENDFUNC

>
>Walter,

How is your entry competitive? You haven't done your own work, just refactored Marcia's entry. Easy to change what's been done rather than come up with a method yourself.