int kiri = 0;
int kanan = 7;
int button = 8;
int state;
int looping;
int pertama;
int counter;
int drkanan;
int drkiri;

void setup() {
  // put your setup code here, to run once:
  pinMode(button, INPUT_PULLUP);
  for (int pertama = 4; pertama < 7; pertama = pertama+2)
  {
    pinMode(pertama, OUTPUT);
  }
  for (int looping = 0; looping <= 7; looping++)
  {
    pinMode(looping, OUTPUT);
  }

  for (counter = 0; counter < 5; counter++)
  {
    for (int pertama = 4; pertama < 7; pertama = pertama+2)
    {
      digitalWrite(pertama, HIGH);
      delay(250);
    }

    for (int pertama = 4; pertama < 7; pertama = pertama+2)
   {
      digitalWrite(pertama, LOW);
      delay(250);
   }
  }

  for (int drkanan = 0; drkanan <= 3; drkanan++)
  {
    pinMode(drkanan, OUTPUT);
  }

  for (int drkiri = 7; drkiri >= 4; drkiri--)
  {
    pinMode(drkiri, OUTPUT);
  }

  
}

void loop() {
  // put your main code here, to run repeatedly:
  if(!digitalRead(button))
  {
    state++;
    if(state>2)state = 0;
    delay(100);
  }

  switch (state)
  {
    case 0:
    soal2();
    break;

    case 1:
    soal3a();
    break;

    case 2:
    soal3b();
    break;
  }

}

void soal2()
{
  
  for (int looping = 0; looping <= 7; looping++){
    digitalWrite(looping, HIGH);
    delay(250);
    digitalWrite(looping, LOW);
    delay(250);
  }

  for (int looping = 7; looping >= 0; looping--)
  {
    digitalWrite(looping, HIGH);
    delay(250);
    digitalWrite(looping, LOW);
    delay(250);
  }
}

void soal3a() 
{
  for (int drkiri = 7; drkiri >= 4; drkiri--)
  {
    digitalWrite(drkiri, HIGH);
    int drkanan = 7-drkiri;
    digitalWrite(drkanan, HIGH);
    delay(250);
    digitalWrite(drkiri, LOW);
    digitalWrite(drkanan, LOW);
    delay(250);
  }

}

void soal3b() 
{
  for (int drkanan = 3; drkanan >= 0; drkanan--)
  {
    digitalWrite(drkanan, HIGH);
    int drkiri = 7-drkanan;
    digitalWrite(drkiri, HIGH);
    delay(250);
    digitalWrite(drkanan, LOW);    
    digitalWrite(drkiri, LOW);
    delay(250);
  }

}