Random_led_four

const int ledRed = 13;
const int ledGreen = 12;
const int ledYellow = 11;
const int ledBlue = 10;
int a;
void setup() {
  // put your setup code here, to run once:
  pinMode(ledRed, OUTPUT);
  pinMode(ledBlue , OUTPUT);
  pinMode(ledGreen, OUTPUT);
  pinMode(ledYellow, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  a = rand()%4;
  Serial.println(a);
  if(a == 0)//ledRed ON
  {
    digitalWrite(ledBlue, LOW);
    digitalWrite(ledGreen, LOW);
    digitalWrite(ledYellow, LOW);
    digitalWrite(ledRed , HIGH);
    delay(1000);//1초
  }
  else if(a == 1)//ledBlue ON
  {
     digitalWrite(ledRed, LOW);
    digitalWrite(ledGreen, LOW);
    digitalWrite(ledYellow, LOW);
    digitalWrite(ledBlue , HIGH);
    delay(1000);//1초
  }
  else if(a == 2)//ledGreen ON
  {
     digitalWrite(ledRed, LOW);
    digitalWrite(ledBlue, LOW);
    digitalWrite(ledYellow, LOW);
    digitalWrite(ledGreen , HIGH);
    delay(1000);//1초
  }
  else//ledYellow ON
  {
     digitalWrite(ledRed, LOW);
    digitalWrite(ledBlue, LOW);
    digitalWrite(ledGreen, LOW);
    digitalWrite(ledYellow , HIGH);
    delay(1000);//1초
  }
}