const int LEDrosso = 4;
const int LEDverde = 3;
const int LEDblu = 2;
const int pulsante = 8;
char LEDarray[3] = {LEDrosso,LEDverde,LEDblu};

int val = 0;

void setup() {
  // put your setup code here, to run once:
pinMode(LEDrosso, OUTPUT);
pinMode(LEDverde, OUTPUT);
pinMode(LEDblu, OUTPUT);

pinMode(pulsante, INPUT_PULLUP);

digitalWrite(LEDrosso, LOW);
digitalWrite(LEDverde, LOW);
digitalWrite(LEDblu, LOW);
delay(1000);
digitalWrite(LEDrosso, HIGH);
digitalWrite(LEDverde, LOW);
digitalWrite(LEDblu, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
if (digitalRead(pulsante) == LOW) {
  digitalWrite(LEDarray[val], LOW);

  val++;

  if(val>2){
    val=0;
  }
digitalWrite(LEDarray[val],HIGH);
delay(100);
}
}