const int DECK_SIZE = 52;
int deck[DECK_SIZE];

unsigned long generateSeed() {
  unsigned long seed = 0;
  for (int i = 0; i < 32; i++) {
    int val = analogRead(A0);  // A0 should be unconnected
    seed = (seed << 1) | (val & 1);  // Use least significant bit
    delay(1); // allow some variation
  }
  return seed;
}

void setup() {
  Serial.begin(9600);
  randomSeed(generateSeed());

  for (int i = 0; i < DECK_SIZE; i++) {
    deck[i] = i;
  }

  for (int i = 0; i < 100; i++) {
    int a = random(DECK_SIZE);
    int b = random(DECK_SIZE);
    int temp = deck[a];
    deck[a] = deck[b];
    deck[b] = temp;
  }

  for (int i = 0; i < DECK_SIZE; i++) {
    printCard(deck[i]);
    Serial.print((i + 1) % 13 == 0 ? "\n" : ", ");
  }
}

void loop() {}

void printCard(int index) {
  const char* suits[] = {"H", "D", "C", "S"};
  const char* ranks[] = {
    "A", "2", "3", "4", "5", "6", "7",
    "8", "9", "10", "J", "Q", "K"
  };
  Serial.print(ranks[index % 13]);
  Serial.print(suits[index / 13]);
}