int trigger=4;
int echo=5;
int r=33,g=26,y=32;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
 
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
  
}

int finding_distance(){
  digitalWrite(trigger, HIGH);
  delay(100);
  digitalWrite(trigger, LOW);
  float a=pulseIn(echo, HIGH);
 float b=a*0.034/2;
 
  if(b>=300){
    pinMode(g,OUTPUT);
    digitalWrite(g,HIGH);
    digitalWrite(r,LOW);
    digitalWrite(y, LOW);

    Serial.println("you safe");}
  else if(b>=200 && b<=300){
    pinMode(y,OUTPUT);
    digitalWrite(y,HIGH);
    digitalWrite(r,LOW);
    digitalWrite(g,LOW);
    Serial.println("unsafe");

  } 
  else {
    pinMode(r,OUTPUT);
    digitalWrite(r,HIGH);
    digitalWrite(g,LOW);
    digitalWrite(y,LOW);
    Serial.println("danger");

  }

  }

void loop() {
  int distance=finding_distance();
  Serial.println(distance);
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}