gistfile1.c

const int ledsLength = 3;
int leds[ledsLength] = {0, 1, 2};
int delaySpeed = 25;
int x = 0;

void turnOnLed(int led);
void turnOffLed(int led);
void turnOnLeds(int leds[]);
void turnOffLeds(int leds[]);
void flashLeds(int leds[], int speed);
void sequenceLeds(int leds[], int speed);
void pulsateSequenceLeds(int leds[], int speed);
void setup();
void loop();

void turnOnLed(int led) {
  digitalWrite(led, HIGH);
  return;
}

void turnOffLed(int led) {
  digitalWrite(led, LOW);
  return;
}

void turnOnLeds(int leds[]) {
  for (size_t i = 0; i < ledsLength; i++) {
    turnOnLed(leds[i]);
  }
  return;
}

void turnOffLeds(int leds[]) {
  for (size_t i = 0; i < ledsLength; i++) {
    turnOffLed(leds[i]);
  }
  return;
}

void flashLeds(int leds[], int speed) {
  turnOnLeds(leds);
  delay(speed);
  turnOffLeds(leds);
  delay(speed);
  return;
}

void sequenceLeds(int leds[], int speed) {
  turnOffLeds(leds);
  delay(speed);
  for (size_t i = 0; i < ledsLength; i++) {
    turnOnLed(leds[i]);
    delay(speed);
  }
  turnOffLeds(leds);
  return;
}

void pulsateSequenceLeds(int leds[], int speed) {
  turnOffLeds(leds);
  for (size_t i = 0; i < ledsLength; i++) {
    for (size_t a = 0; a < 10; a++) {
      turnOnLed(leds[i]);
      delay(25);
      turnOffLed(leds[i]);
      delay(25);
    }
  }
  turnOffLeds(leds);
}

void setup() {
  for (size_t i = 0; i < ledsLength; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  if (x < 25) {
    for (size_t i = 0; i < ledsLength; i++) {
      digitalWrite(leds[i], HIGH);
      delay(delaySpeed);
      digitalWrite(leds[i], LOW);
      delay(delaySpeed);
    }
  }
  
  if (x > 25 and x < 50) {
    flashLeds(leds, delaySpeed);
  }
  
  if (x > 50 and x < 54) {
    pulsateSequenceLeds(leds, 500);
  }
  
  if (x > 54) {
    x = 0;
  } else {
    x++;
  }
}