#define redled 0
#define blueled 1
#define greenled 2

int redledstate = LOW;
int blueledstate = LOW;
int greenledstate = LOW;

unsigned long currenttime = 0;
unsigned long prevredledtime = 0;
unsigned long prevblueledtime = 0;
unsigned long prevgreenledtime = 0;
const unsigned long delayredled = 1000;
const unsigned long delayblueled = 500;
const unsigned long delaygreenled = 250;

void blinkredled() {
  if (currenttime - prevredledtime >= delayredled) {
    prevredledtime = currenttime;

    if (redledstate == LOW) {
      redledstate = HIGH;
    }

    else {
      redledstate = LOW;
    }

    digitalWrite (redled, redledstate);
  }
}

void blinkblueled() {
  if (currenttime - prevblueledtime >= delayblueled) {
    prevblueledtime = currenttime;

    if (blueledstate == LOW) {
      blueledstate = HIGH;
    }

    else {
      blueledstate = LOW;
    }

    digitalWrite (blueled, blueledstate);
  }
}

void blinkgreenled() {
  if (currenttime - prevgreenledtime >= delaygreenled) {
    prevgreenledtime = currenttime;

    if (greenledstate == LOW) {
      greenledstate = HIGH;
    }

    else {
      greenledstate = LOW;
    }

    digitalWrite (greenled, greenledstate);
  }
}

void setup() {
pinMode (redled, OUTPUT);

}

void loop() {
currenttime = millis();
blinkredled();
blinkblueled();
blinkgreenled();

}