#include <stdio.h>
#include <math.h> 

// macro = text substitution
#define PI 3.14159265

// parametric macro:
// DOUBLE EVALUATION = DOUBLE SIDE EFFECT
#define SINDEG2(ALPHA) (sin(PI/180.0*( (ALPHA)+(ALPHA) )))

int main(void) {
  double alpha;
  for (alpha=0; alpha<361; ) { // empty incrementation instuction
                               // NOT RECOMMENDED
    // OPERATION ON ‘ALPHA’ MAY BE UNDEFINED:
    printf("%5.1lf\t%8.4lf\n", alpha+30.0, SINDEG2(alpha+=30.0));
  }
  return 0;
}