#include

Servo myservo;

enum $\{$Idle$,$ Degree$0,$ Degree$180\}$;

enum $\{$IdleDC$,$ Forward, Backward$\}$;

int DC$1=9$;

int DC$2=10$;

int LED $=8$;

int SB $=6$;

int CB $=5$;

int FB $=4$;

int BB $=3$;

int current;

int currentDC;

void setup$()\{$

Serial.begin$(9600)$;

pinMode$($DC$1,$ OUTPUT$)$;

pinMode$($DC$2,$ OUTPUT$)$;

pinMode$($LED$,$ OUTPUT$)$;

pinMode$($SB$,$ INPUT$\_$PULLUP$)$;

pinMode$($CB$,$ INPUT$\_$PULLUP$)$;

pinMode$($FB$,$ INPUT$\_$PULLUP$)$;

pinMode$($BB$,$ INPUT$\_$PULLUP$)$;

myservo.attach$(11)$;

current $=$ Idle;

currentDC $=$ IdleDC;

$\}$

void loop$()\{$

switch $($current$)\{$

case Idle:

digitalWrite$($LED$,$ LOW$)$;

myservo.write$(90)$;

delay$(15)$;

if $($digitalRead$($SB$)==0)$

current $=$ Degree$0$;

if $($digitalRead$($CB$)==0)$

DCFSM$()$;

break;

case Degree$0$:

digitalWrite$($LED$,$ LOW$)$;

myservo.write$(0)$;

delay$(15)$;

if $($digitalRead$($SB$)==0)$

current $=$ Degree$180$;

if $($digitalRead$($CB$)==0)$

DCFSM$()$;

break;

case Degree$180$:

break;

$\}$

$\}$

void DCFSM$()\{$

while $($true$)\{$

switch $($currentDC$)\{$

case IdleDC:

digitalWrite$($DC$1,$ LOW$)$;

digitalWrite$($DC$2,$ LOW$)$;

digitalWrite$($LED$,$ HIGH$)$;

if $($digitalRead$($FB$)==0)$

currentDC $=$ Forward;

if $($digitalRead$($BB$)==0)$

currentDC $=$ Backward;

break;

case Forward:

break;

case Backward:

digitalWrite$($LED$,$ LOW$)$;

digitalWrite$($DC$1,$ LOW$)$;

digitalWrite$($DC$2,$ HIGH$)$;

delay$(3000)$;

currentDC $=$ IdleDC;

break;

$\}$

if $($digitalRead$($SB$)==0)$

break;

$\}$

$\}$

complete missing part of the code $($ where the line is $)$