int a = 1;
int b = 2;
int c = 3;
int d = 4;
int e = 5;
int f = 6;
int g = 7;
int buttonUp = 11;
int buttonDown = 12;
int buttonStateUp = 0;
int buttonStateDown = 0;
int lastButtonStateUp = 0;
int lastButtonStateDown = 0;
int count = 0;

unsigned long lastDebounceTimeUp = 0;
unsigned long lastDebounceTimeDown = 0;
unsigned long debounceDelay = 10;

void setup() {
  pinMode(a, OUTPUT);
  pinMode(b, OUTPUT);
  pinMode(c, OUTPUT);
  pinMode(d, OUTPUT);
  pinMode(e, OUTPUT);
  pinMode(f, OUTPUT);
  pinMode(g, OUTPUT);
  pinMode(buttonUp, INPUT);
  pinMode(buttonDown, INPUT);
}

void displayNumber(int num) {
  switch (num) {
    case 0:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, LOW);
      break;
    case 1:
      digitalWrite(a, LOW); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, LOW);
      break;
    case 2:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, LOW); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, LOW); digitalWrite(g, HIGH);
      break;
    case 3:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, HIGH);
      break;
    case 4:
      digitalWrite(a, LOW); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, HIGH); digitalWrite(g, HIGH);
      break;
    case 5:
      digitalWrite(a, HIGH); digitalWrite(b, LOW); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, LOW); digitalWrite(f, HIGH); digitalWrite(g, HIGH);
      break;
    case 6:
      digitalWrite(a, HIGH); digitalWrite(b, LOW); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, HIGH);
      break;
    case 7:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, LOW); digitalWrite(e, LOW); digitalWrite(f, LOW); digitalWrite(g, LOW);
      break;
    case 8:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, HIGH); digitalWrite(f, HIGH); digitalWrite(g, HIGH);
      break;
    case 9:
      digitalWrite(a, HIGH); digitalWrite(b, HIGH); digitalWrite(c, HIGH); digitalWrite(d, HIGH); digitalWrite(e, LOW); digitalWrite(f, HIGH); digitalWrite(g, HIGH);
      break;
  }
}

void loop() {
  int readingUp = digitalRead(buttonUp);
  int readingDown = digitalRead(buttonDown);
  
  if (readingUp != lastButtonStateUp) {
    lastDebounceTimeUp = millis();
  }
  
  if (readingDown != lastButtonStateDown) {
    lastDebounceTimeDown = millis();
  }
  
  if ((millis() - lastDebounceTimeUp) > debounceDelay) {
    if (readingUp != buttonStateUp) {
      buttonStateUp = readingUp;
      if (buttonStateUp == HIGH) {
        count++;
        if (count > 9) {
          count = 0;
        }
        displayNumber(count);
      }
    }
  }

  if ((millis() - lastDebounceTimeDown) > debounceDelay) {
    if (readingDown != buttonStateDown) {
      buttonStateDown = readingDown;
      if (buttonStateDown == HIGH) {
        count--;
        if (count < 0) {
          count = 9;
        }
        displayNumber(count);
      }
    }
  }

  lastButtonStateUp = readingUp;
  lastButtonStateDown = readingDown;
}