#define LED_Z  2
#define LED_PG 3
#define LED_C  4
#define LED_PD 5
#define LED_B  6

int leds[] = {LED_Z, LED_PG, LED_C, LED_PD, LED_B};

void forAllLeds(void (*action)(int)) {
  for (int i = 0; i < 5; i++) {
    action(leds[i]);
  }
}

void setup() {
  // put your setup code here, to run once:
  forAllLeds([](int led) {
    pinMode(led, OUTPUT);
  });
  turnOffAll();
}

void turnOffAll() {
  forAllLeds([](int led) {
    digitalWrite(led, LOW);
  });
}

void turnOnAll() {
  forAllLeds([](int led) {
    digitalWrite(led, HIGH);
  });
}

int ledIndex = 0;

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(leds[ledIndex], LOW);
  ledIndex = (ledIndex + 1) % 5;
  digitalWrite(leds[ledIndex], HIGH);
  delay(1000);

}