sum (adding 2 numbers ) without plus operator

Question

Can anyone explain the logic how to add a and b?

#include 

int main()
{
     int a=30000, b=20, sum;
     char *p;
             


        

Answer 1

C standard says that E1[E2] is equivalent to *((E1) + (E2)). Therefore:

 &p[b] = &*((p) + (b)) = ((p) + (b)) = ((a) + (b)) = a + b