Efficient way

How to fast multiply a number by 7?

Representing binary in C code

Hi all

    It has been a long time... :)

    Hey does any one know if it is possible to add prefix before a number to represent binary

    For example
        unsigned char a = 0xF0;    This is for hexadecimal
       
Is there a similar representation for binary and octal?
I already tried

    unsigned char a = 0b11110000;

It is possible in MPLAB but not with gcc on linux.
Any solutions...???