#define LED_L 10
#define DelayTime 200
const int Led[ LED_L ] = { 2,3,4,5,6,7,8,9,10,11 };

void setup() {
  for(int i=0;i<LED_L;i++){
    pinMode(Led[ i ] , OUTPUT);
    digitalWrite(Led[ i ],HIGH); //先讓 LED 初始值為暗
  }
}

void loop() {
  int i,j,k,t;
  for(i=0; i<LED_L; i++)
    for(j=-i; j<LED_L; j++){
      for(k=0; k<=i; k++)
        if((k+j>=0)&&(k+j<LED_L))
          digitalWrite(Led[ k+j ], LOW);
      delay(DelayTime);
      for(t=0; t<LED_L; t++) digitalWrite(Led[ t ], HIGH);
  }
}