int estado;

void setup() {
 for(int led = 11; led > 1; led = led - 1){
  pinMode(led, OUTPUT);
 }
}
void loop() {
  estado = random(1,3);

  if(estado == 1){

 for(int i = 11; i > 1; i = i - 1){
  digitalWrite(i, HIGH);
  delay(100);
  digitalWrite(i, LOW);
  delay(100);
 }
  for(int i = 2; i < 11; i = i + 1){
  digitalWrite(i, HIGH);
  delay(100);
  digitalWrite(i, LOW);
  delay(100);
 }
}
//-------------------------
 if(estado == 2){

 for(int i = 11; i > 1; i = i - 1){
  digitalWrite(i, HIGH);
 }
 delay(500);
  for(int i = 2; i < 12; i = i + 1){
  digitalWrite(i, LOW);
 }
 delay(500);
}
}