#define _USE_MATH_DEFINES 
#include <math.h>

int main()
{
   double  s, f=0.0, fStep=0.1*M_PI;
   int     n=0;

   do
   {
       s = sin(f);
       f += fStep;
       n++;
   }
   while( f < M_PI );

   assert( n < 11 );
}


