// Pin definitions for LEDs
const int redLED = 3;
const int yellowLED = 4;
const int greenLED = 5;

// Seven segment display pins
const int sevSegPins[] = {7, 8, 9, 10, 11, 12, 13};

// Digits for 7-segment display
const byte numbers[10] = {
  B11000000, // 0
  B11111001, // 1
  B10100100, // 2
  B10110000, // 3
  B10011001, // 4
  B10010010, // 5
  B10000010, // 6
  B11111000, // 7
  B10000000, // 8
  B10010000  // 9
};

int counter = 0; // Counter for 7-segment display

void setup() {
  // Initialize LEDs as output
  pinMode(redLED, OUTPUT);
  pinMode(yellowLED, OUTPUT);
  pinMode(greenLED, OUTPUT);

  // Initialize seven-segment pins as output
  for (int i = 0; i < 7; i++) {
    pinMode(sevSegPins[i], OUTPUT);
  }
}

void loop() {
  // Red light on for 3 seconds
  digitalWrite(redLED, HIGH);
  displayNumber(counter);
  delay(3000);
  digitalWrite(redLED, LOW);

  // Yellow light on for 3 second
  counter = (counter + 1) % 10;
  digitalWrite(yellowLED, HIGH);
  displayNumber(counter);
  delay(3000);
  digitalWrite(yellowLED, LOW);

  // Green light on for 3 seconds
  counter = (counter + 1) % 10;
  digitalWrite(greenLED, HIGH);
  displayNumber(counter);
  delay(3000);
  digitalWrite(greenLED, LOW);

  // Increment counter for next cycle
  counter = (counter + 1) % 10;
}

// Function to display a number on the 7-segment display
void displayNumber(int num) {
  byte segments = numbers[num];
  for (int i = 0; i < 7; i++) {
    digitalWrite(sevSegPins[i], bitRead(segments, i));
  }
}