I do \"#include \" at the top of the source.
\"#include \"
Example compilation:
/usr/bin/colorgcc -std=c99 -fgnu89-inline -g -Wall -I
I use rand() and srand(). BTW: Did you forget a header or two? At least the second warning tells me so.
Try including math.h. (Just remembered we always had issues with math library and had to actually force link it with -lm).