Thoroughly explain the purpose of this program. #include  int mystery2 (const char *); /* prototype */ int main(void) { char string[80]; /* create char array */ printf ("Enter a string: "); scanf ("%s", string); printf ("%d ", mystery2 (string)); return 0; /* indicates successful termination */ } /* What does this function do? */ int mystery2 (const char *s) { int x; /* counter */ /* loop through string */ for (x = 0; *s != '\0'; s++) { ++x; } /* end for */ return x; } /* end function mystery2 */