int led[5] = {LOW, LOW, LOW, LOW, LOW};
int mapping[5] = {13, 12, 11, 10, 9};
int soDoan = 0;
int soBiMat = 0;

void driveLed(int i, int a, int x) {
  if (a > x) {
    //So lon hon BLINK
    if (led[i] == LOW) {
      led[i] = HIGH;
    }
    else {
      led[i] = LOW;
    }
    digitalWrite(mapping[i], led[i]);
    delay(100);
  }
  else if (a < x) {
    //So nho hon OFF
    digitalWrite(mapping[i], LOW);
  }
  else {
    //So dung ON
    digitalWrite(mapping[i], HIGH);
  }
}

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
Serial.println("Nhap so bi mat (5 chu so): ");
soBiMat = Serial.parseInt();
pinMode(13, OUTPUT);
pinMode(12, OUTPUT);
pinMode(11, OUTPUT);
pinMode(10, OUTPUT);
pinMode(9, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (Serial.available()) {
    Serial.print("Hay doan so bi mat: ");
    soDoan = Serial.parseInt();
    Serial.println(soDoan);
  }
  int temp_soDoan = soDoan;
  int temp_soBiMat = soBiMat;
  for (int j=0; j<5; j++) {
    int a = temp_soDoan % 10;
    int x = temp_soBiMat % 10;
    driveLed(j, a, x);
    temp_soDoan = temp_soDoan / 10;
    temp_soBiMat = temp_soBiMat / 10;
  }
}