can someone suggest me ho to get good compiler that can work efficiently ? what about gnu/gcc?

The downloaded version of GCC isn't a trial version or an educational version. It's the real thing. And it handles large programs about as well as any other high quality compiler.

gcc is especially good when used in conjunction with makefiles...
makefiles are your friend... :)

can someone give idea how to get compilrrs free or by payingfor cpp

can someone give idea how to get compilrrs free or by payingfor cpp

If you use MS-Windows operating system you can get Dev-C++ from www.bloodshed.net. Otherwise if you use *nix you can get gcc and g++ from www.gnu.org. Both are free.