//declaring the variables
int redLed1 = 23;
int redLed2 = 22;
int redLed3 = 21;
int redLed4 = 19;
int greenLed1 = 18;
int greenLed2 = 5;
int greenLed3 = 17;
int greenLed4 = 16;

int sw1 = 34;
int sw2 = 35;
int sw3 = 32;
int sw4 = 33;

void setup() {
  pinMode(redLed1, OUTPUT);
  pinMode(redLed2, OUTPUT);
  pinMode(redLed3, OUTPUT);
  pinMode(redLed4, OUTPUT);
  pinMode(greenLed1, OUTPUT);
  pinMode(greenLed2, OUTPUT);
  pinMode(greenLed3, OUTPUT);
  pinMode(greenLed4, OUTPUT);
  pinMode(sw1, INPUT_PULLUP);
  pinMode(sw2, INPUT_PULLUP);
  pinMode(sw3, INPUT_PULLUP);
  pinMode(sw4, INPUT_PULLUP);
}

void loop() {
  if(digitalRead(sw1)==1){
    //diverging
    digitalWrite(redLed4, HIGH);
    digitalWrite(greenLed1, HIGH);
    delay(500);
    digitalWrite(redLed3, HIGH);
    digitalWrite(greenLed2, HIGH);
    digitalWrite(redLed4, LOW);
    digitalWrite(greenLed1, LOW);
    delay(500);
    digitalWrite(redLed2, HIGH);
    digitalWrite(greenLed3, HIGH);
    digitalWrite(redLed3, LOW);
    digitalWrite(greenLed2, LOW);
    delay(500);
    digitalWrite(redLed1, HIGH);
    digitalWrite(greenLed4, HIGH);
    digitalWrite(redLed2, LOW);
    digitalWrite(greenLed3, LOW);
    delay(500);
    digitalWrite(redLed1, LOW);
    digitalWrite(greenLed4, LOW);
  }
  if(digitalRead(sw2)==1){
   //diverging
    digitalWrite(redLed1, HIGH);
    digitalWrite(greenLed4, HIGH);
    delay(500);
    digitalWrite(redLed3, HIGH);
    digitalWrite(greenLed2, HIGH);
    digitalWrite(redLed1, LOW);
    digitalWrite(greenLed4, LOW);
    delay(500);
    digitalWrite(redLed4, HIGH);
    digitalWrite(greenLed1, HIGH);
    digitalWrite(redLed3, LOW);
    digitalWrite(greenLed2, LOW);
    delay(500);
    digitalWrite(redLed3, HIGH);
    digitalWrite(greenLed2, HIGH);
    digitalWrite(redLed4, LOW);
    digitalWrite(greenLed1, LOW);
    delay(500);
    digitalWrite(redLed2, HIGH);
    digitalWrite(greenLed3, HIGH);
    digitalWrite(redLed3, LOW);
    digitalWrite(greenLed2, LOW);
    delay(500);
     digitalWrite(redLed1, HIGH);
    digitalWrite(greenLed4, HIGH);
    digitalWrite(redLed2, LOW);
    digitalWrite(greenLed3, LOW);
  }
  if(digitalRead(sw3)==1){
    digitalWrite(redLed1, HIGH);
    delay(500);
    digitalWrite(redLed1, LOW);
    digitalWrite(redLed2, HIGH);
    delay(500);
    digitalWrite(redLed2, LOW);
    digitalWrite(redLed3, HIGH);
    delay(500);
    digitalWrite(redLed3, LOW);
    digitalWrite(redLed4, HIGH);
    delay(500);
    digitalWrite(redLed4, LOW);
    digitalWrite(greenLed1, HIGH);
    delay(500);
    digitalWrite(greenLed2, HIGH);
    digitalWrite(greenLed1, LOW);
    delay(500);
    digitalWrite(greenLed3, HIGH);
    digitalWrite(greenLed2, LOW);
    delay(500);
    digitalWrite(greenLed4, HIGH);
    digitalWrite(greenLed3, LOW);
    delay(500);
    digitalWrite(greenLed4, LOW);
    digitalWrite(greenLed3, HIGH);
    delay(500);
    digitalWrite(greenLed3, LOW);
    digitalWrite(greenLed2, HIGH);
    delay(500);
    digitalWrite(greenLed2, LOW);
    digitalWrite(greenLed1, HIGH);
    delay(500);
    digitalWrite(redLed4, HIGH);
    digitalWrite(greenLed1, LOW);
    delay(500);
    digitalWrite(redLed4, LOW);
    digitalWrite(redLed3, HIGH);
    delay(500);
    digitalWrite(redLed3, LOW);
    digitalWrite(redLed2, HIGH);
    delay(500);
    digitalWrite(redLed2, LOW);
    digitalWrite(redLed1, HIGH);
    delay(500);
    digitalWrite(redLed1, LOW);
  }
  if(digitalRead(sw4)==1){
   digitalWrite(redLed1, HIGH);
   digitalWrite(redLed3, HIGH);
   digitalWrite(greenLed1, HIGH);
   digitalWrite(greenLed3, HIGH);
   delay(500);
   digitalWrite(redLed1, LOW);
   digitalWrite(redLed3, LOW);
   digitalWrite(greenLed1, LOW);
   digitalWrite(greenLed3, LOW);
   digitalWrite(redLed2, HIGH);
   digitalWrite(redLed4, HIGH);
   digitalWrite(greenLed2, HIGH);
   digitalWrite(greenLed4, HIGH);
   delay(500);
   digitalWrite(redLed2, LOW);
   digitalWrite(redLed4, LOW);
   digitalWrite(greenLed2, LOW);
   digitalWrite(greenLed4, LOW);

  }
}