Hi,
Is it recommended to use cstdio,cstring,cmath in c++? I was writing a program that needed pow , strlen and sprintf ... for that the only way I could do it was to include these 3 headers. Is there a better C++ way to do it?
Thanks
Not sure I agree with this :) It sounds like he's dealing with C-style strings, not C++ strings. The question I would have is: should he not be using std::basic_string<T> instead of NULL terminated strings along with the IO manipulation features of C++ instead of sprintf? cheers :)
OJ
2010-03-21 22:33:01
+10
A:
You can use std::stringstream instead of sprintf and std::string instead of C-style strings. But C++ just uses the C library for math functions.
dan04
2010-03-21 22:09:58
But it's all for using char* strings. If you switch to C++'s string class you get it all in the string header. (O.K., sometimes you might need algorithm as well)And it's preferred to use C++'s string than a char* if possible.
Shiroko
2010-03-21 22:44:22
memcpy and memset are superceded by std::copy and std::fill. For POD types, the GNU implementation falls through to memcpy. Not sure about memset.
Potatoswatter
2010-03-22 07:14:07
+3
A:
For math functions, <cmath> is the correct way; however, for I/O, you should be using <iostream>, <sstream>, <fstream>, and friends. For string manipulation, <string> is the way to go.
Michael Aaron Safyan
2010-03-21 22:49:52
@osgx, not sure I buy that. scanf/printf have to deal with a lot more formatting than iostreams does. Which implementation did you use? Any reasonable implementation of iostream should be at least as fast.
Michael Aaron Safyan
2010-03-22 07:41:05
@Michael Aaron Safyan, on our olymp problem was with `sync_with_stdio`. libstdc++'s iostream from gcc has this enabled in Linux. After turning this off speed of iostream increased
osgx
2010-03-22 10:32:58
+1
A:
cmath isn't really superseded in C++, since there's really nothing to make them better. However, stringstreams/iostreams are far far superior to the cstring and cstdio lot.
If you have a C string, you can convert to a std::string quite easily, and the same for back again. If you're using strings, ALWAYS use the C++ string libraries over strlen, sprintf, and that.
DeadMG
2010-03-21 23:00:12