Fabio,

>VFP CHRTRAN, when don't remove character, don't use a O(n)
>( because this not exist ), but it use a O(n*m) program.

Sorry, to disrupt your belief, but it can be done O(n) without regard to the length of the second and third arguments (assuming that is what the m means in your above calculation). A simple 256 character transformation matrix can be constructed, where the input character is used as an index into the matrix to get the output character. The translation line in the C++ code would look like this then:

  *cpOut++ = XLatMatrix[*cpIn]; // translate the character and advance the output pointer

>Any developer, with a little backgroud, known that this task can to be make
>in O((n+m)*Log(min(n,m))).

So I guess that makes me a little better than any developer with a little background. *bg*