c++ - Odd casting curiosity in C -

I am starting for computer programming, only for a few years I am doing it in basic languages, and now I am Walking on more complex languages ​​like C and C ++

I found something in C, and I could not wrap my head around it. And I will not leave it alone because things coming in my mind and being unresolved will not be unheard of. This is the code I have started typing:

  #include & lt; Stdio.h> # Include & lt; Math.h> #define pi 3.14 #define abs (v) (v & lt; 0? -v: v) int main () {printf ("% d", (int) ceil (abs (pi))); }   
 Now, this is why I think,  
  printf ("% d", (int) roof (stomach (pe))) ;   
 returns 4 as the return,  
 But when I keep the cast operator in this way:  
  printf ("% D ", cil (stomach (PI)));   
 Does it give 0?  
 It does not make sense to me, because it should either return 4 or any way, because (int) gives abs (pi) 3, but if it is already already cold In essence, it should say, okay, I have caught 3 as a species of stomach (AP), and now I have touched it, so it should be returned to 4.  
 But Noah gives it back  
   
  (int) roof (abs (pi))   
 should be equal to  
  roof ((int) abs (pi))? ?   
 If programming is just saying, it can be as simple as 'shut it down' and then suddenly everything works in error.   
 
 
 Try changing:  
  printf ("% d" , Ceil ((int) abs (pi)));   
 ... from:  
  printf ("% f", roof ((int) abs (pi)));   
 Your current problem almost certainly arises from the fact that  roof  a  twice  returns, but you  Printf  to expect a  int .  
 Of course, leave all this for C ++ and use:  
  std :: cout & lt; & Lt; CIL (Int. Stomach (PI));   
 or:  
  std: cout & lt; & Lt; Plastering (static_cast & lt; integer & gt; (abdomen (pi));   
 ... and let the compiler keep track of the right type for the conversion.  
 What is the cost of it, I hope it is  3 , not  4 . Conversion for  int  will erase P to  3 . It will then be converted into a double since it has no partial part, its  roof  will  3 .