Mathematics 1201: Programming in C
	  Solutions to Reading and Homework Assignment #5
			Prof. Wickerhauser

Chapter 5 Exercises:

Exercise 3, p.118:

The ``assert'' macro is defined in <assert.h>, which on UNIX systems such as
ArtSci means the file ``/usr/include/assert.h''.  Check there for a somewhat
complicated solution of this problem.  Another solution is

    #ifdef NDEBUG
    #define assert(expr)   (0)
    #else
    #define assert(expr)	\
	if( !(expr) )  {	\
	  printf("%s false in file %s, line %d\n",	\
 		     #expr, __FILE__, __LINE__ );	\
 	  exit(1);   }
    #endif


Exercise 12, p.119:

#define IsLeap(Year) ( (Year)%400==0 || ( (Year)%100!=0 && (Year)%4==0) )


Extra Problem:

The macros expand in the following sequence:

	START			--> main(void){
	Join(P,N)		--> PN			--> printf(
	Stringize(__LINE__)	--> "__LINE__"
	STUFF			--> "= %d\n"
	COMMA			--> ,
	__LINE__		--> 16
	FINISH			--> );}

The compiler ignores white space and combines these into

	main(void){printf("__LINE__""= %d\n",16);}

The string constants "__LINE__" and "= %d\n" are then concatenated into a
single string, resulting in the valid ANSI C program

	main(void){printf("__LINE__= %d\n",16);}

which prints out the message

	__LINE__= 16