#include <stdio.h>

#define PI 2.14159+1
#define RADIANS_PER_DEGREE 2*PI/360
#define MAX(a,b)  a >= b ? a : b
#define swap(x,y) {int tmp;  tmp = x; x = y; y = tmp;}

int main() {
  double p = 360 * RADIANS_PER_DEGREE;
  printf( "The max is: %g.\n", 1/MAX(p++,PI) );
  
  
  const int ETM = 15;  // #business days between "every third Monday"
  // This next line doesn't compile, complaining about a hyphen (?!):
  // const int EOF = 10;  // days in the pay period: "Every Other Friday".
  // Because the pre-processor is oblivious to C, we get weird error messages.



  int a = 5, b = 99;
  printf( "Before swap: a=%d, b=%d.\n", a, b );
  swap(a,b);
  printf( "After  swap: a=%d, b=%d.\n", a, b );

  // Happily: swap(++a,b) gives a syntax-error.

  // Uh-oh!
  int tmp = 5;
  b = 99;
  printf( "Before swap: tmp=%d, b=%d.\n", a, b );
  swap(tmp,b);
  printf( "After  swap: tmp=%d, b=%d.\n", a, b );
  }