The output is 9 but why?

Question

char *s = "a string";
char *p = s;
while(*p++);
printf("%d", (int)(p-s));

Answer 1

Coder Kitten after while loop p value be "g", so answer should be g-a=5.
Am I right?

Answer 2

Coder Kitten so, p points to \0 or NULL

Answer 3

Answer is 9 right?