// Set three variables for the three LED pins
int redPin = 13;
int greenPin = 12;
int bluePin = 11;

// In the setup fucntion, set all LED pins to output
void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  // Create an array with the LED pins
  int pinsToUse[] = {redPin, greenPin, bluePin};
  // Create an array with three positions that is randomly
  // either 0 (the LED is off) or 1 (the LED is on)
  int ledsOnOrder[] = {random(2), random(2), random(2)};
  // Use a for loop to set the LEDs on or off
  for (int i = 0; i <= 2; i++) {
    // Use digitalWrite to set the LEDs to on or off
    digitalWrite(pinsToUse[i], ledsOnOrder[i]);
  }
  // Wait for half a second
  delay(500);
}