// for traffic light 1
int redPin1 = 2; // connect red LED to digital pin 2
int yellowPin1 = 3; // connect yellow LED to digital pin 3
int greenPin1 = 4; // connect green LED to digital pin 4

// for traffic light 2
int greenPin2 = 5; // connect green LED to digital pin 5
int yellowPin2 = 6; // connect yellow LED to digital pin 6
int redPin2 = 7; // connect red LED to digital pin 7

// for traffic light 3
int greenPin3 = 8; // connect green LED to digital pin 8
int yellowPin3 = 9; // connect yellow LED to digital pin 9
int redPin3 = 10; // connect red LED to digital pin 10

void setup() {
  pinMode(redPin1, OUTPUT);
  pinMode(yellowPin1, OUTPUT);
  pinMode(greenPin1, OUTPUT);

  pinMode(redPin2, OUTPUT);
  pinMode(yellowPin2, OUTPUT);
  pinMode(greenPin2, OUTPUT);


  pinMode(redPin3, OUTPUT);
  pinMode(yellowPin3, OUTPUT);
  pinMode(greenPin3, OUTPUT);
}

void loop() {
// rule 1
  digitalWrite(greenPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(greenPin3, HIGH);

  digitalWrite(redPin1, LOW);
  digitalWrite(yellowPin1, LOW);

  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(yellowPin3, LOW);
  delay(25000); // wait 25 seconds

 // sub-rule 1
  digitalWrite(yellowPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(yellowPin3, HIGH);

  digitalWrite(redPin1, LOW);
  digitalWrite(greenPin1, LOW);
  
  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5 
 

// rule 2

//sub-rule 2-1
  digitalWrite(redPin1, HIGH);
  digitalWrite(yellowPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(yellowPin1, LOW);
  digitalWrite(greenPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(yellowPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5 

//sub-rule 2-2
  digitalWrite(redPin1, HIGH);
  digitalWrite(greenPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(yellowPin1, LOW);
  digitalWrite(greenPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(yellowPin2, LOW);

  digitalWrite(yellowPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(20000); // wait 20

//sub-rule 2-3
  digitalWrite(redPin1, HIGH);
  digitalWrite(yellowPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(yellowPin1, LOW);
  digitalWrite(greenPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(yellowPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5
  
//Rule -3

//sub-rule 3-1
  digitalWrite(yellowPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(yellowPin3, HIGH);

  digitalWrite(redPin1, LOW);
  digitalWrite(greenPin1, LOW);
  
  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5

//sub-rule 3-2
  digitalWrite(greenPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(greenPin3, HIGH);

  digitalWrite(yellowPin1, LOW);
  digitalWrite(redPin1, LOW);
  
  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(yellowPin3, LOW);
  delay(20000); // wait 20
  
//sub-rule 3-3
  digitalWrite(yellowPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(yellowPin3, HIGH);

  digitalWrite(greenPin1, LOW);
  digitalWrite(redPin1, LOW);
  
  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5


// Rule -4  
//sub-rule 4-1
  digitalWrite(redPin1, HIGH);
  digitalWrite(yellowPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(greenPin1, LOW);
  digitalWrite(yellowPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(greenPin3, LOW);
  digitalWrite(yellowPin3, LOW);
  delay(5000); // wait 5   

//sub-rule 4-2
  digitalWrite(redPin1, HIGH);
  digitalWrite(greenPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(greenPin1, LOW);
  digitalWrite(yellowPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(yellowPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(yellowPin3, LOW);
  delay(20000); // wait 20

//sub-rule 4-3
  digitalWrite(redPin1, HIGH);
  digitalWrite(yellowPin2, HIGH);
  digitalWrite(redPin3, HIGH);

  digitalWrite(greenPin1, LOW);
  digitalWrite(yellowPin1, LOW);
  
  digitalWrite(redPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(yellowPin3, LOW);
  delay(5000); // wait 5 

//sub-rule 4-4
  digitalWrite(yellowPin1, HIGH);
  digitalWrite(redPin2, HIGH);
  digitalWrite(yellowPin3, HIGH);

  digitalWrite(greenPin1, LOW);
  digitalWrite(redPin1, LOW);
  
  digitalWrite(yellowPin2, LOW);
  digitalWrite(greenPin2, LOW);

  digitalWrite(redPin3, LOW);
  digitalWrite(greenPin3, LOW);
  delay(5000); // wait 5 
 
  }