strange result on macro expansion

Question

Consider the following code snippet

#include
#define A -B
#define B -C
#define C 5

int main()
{
  printf(\"The value of A is %d\\n\", A);
  r         


        

Answer 1

The preprocessor introduces a space in-between the expansion of B and C:

#define A -B
#define B -C
#define C 5
A

with output (generated via cpp < test.c)

# 1 "test.c"
# 1 "" 1
# 1 "" 3
# 329 "" 3
# 1 "" 1
# 1 "" 2
# 1 "test.c" 2



- -5