int leds[] = {2, 5, 4};
int n = 3;

void setup() {
  for (int i = 0; i < n; i++) pinMode(leds[i], OUTPUT);
}

void loop() {
  // Pattern 1: วิ่งซ้าย-ขวา
  for (int i = 0; i < n; i++) {
    digitalWrite(leds[i], HIGH);
    delay(500);
    digitalWrite(leds[i], LOW);
  }

  for (int i = n-2; i > 0; i--) {
    digitalWrite(leds[i], HIGH);
    delay(500);
    digitalWrite(leds[i], LOW);
  }

  // Pattern 2: ทุกดวงติดพร้อมกัน
  for (int i = 0; i < n; i++) digitalWrite(leds[i], HIGH);
  delay(800);
  for (int i = 0; i < n; i++) digitalWrite(leds[i], LOW);
  delay(800);
}