//chaser led circuit
int ledpin[] = {2,3,4,5,6,7,8,9,10,11};

void setup() {
  // put your setup code here, to run once:
  for(int i=0;i<10;i++){
    pinMode(ledpin[i], OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i=0;i<10;i++){
    digitalWrite(ledpin[i], HIGH);
    delay(100);
    digitalWrite(ledpin[i], LOW);
  }
  for(int i=10;i>0;i--){
    digitalWrite(ledpin[i], HIGH);
    delay(100);
    digitalWrite(ledpin[i], LOW);
  }
}