int ledPinRed = 8;
int ledPinYellow = 9;
int ledPinGreen = 10;

int btnPinRed = 11;
int btnPinYellow = 12;
int btnPinGreen = 13;

void setup() {
  // register lampu led
  int listLedPin[3] = {ledPinRed, ledPinYellow, ledPinGreen};
  initPinMode(listLedPin, OUTPUT);

  // inisial lampu led
  initPowerLed(listLedPin);
  
  // register button
  int listBtnPin[3] = {btnPinRed, btnPinYellow, btnPinGreen};
  initPinMode(listBtnPin, INPUT);
}

void loop() {
  // jika saklar merah diklik
  togglePowerLed(btnPinRed, ledPinRed);
  // jika saklar kuning diklik
  togglePowerLed(btnPinYellow, ledPinYellow);
  // jika saklar hijau diklik
  togglePowerLed(btnPinGreen, ledPinGreen);
}

void initPinMode(int (&array)[3], int mode) {
  for (int element : array) {
    pinMode(element, mode);
  }
}

void initPowerLed(int (&array)[3]) {
  for (int element : array) {
    digitalWrite(element, LOW);
  }
}

void togglePowerLed(int btnPinType, int ledPinType) {
  if (digitalRead(btnPinType) == HIGH) {
    digitalWrite(ledPinType, HIGH);
  } else {
    digitalWrite(ledPinType, LOW);
  }
}