Quiz buzzer for three players on an Arduino Uno

// A quiz buzzer: whoever presses first gets the light and the beep.
//
//   answer buttons -> pins 2, 3, 4, reset button -> pin 9 (each to GND,
//                     read with INPUT_PULLUP)
//   player LEDs    -> pins 6, 7, 8, through 220 ohm each
//   ready LED      -> pin 10, through 220 ohm
//   buzzer         -> pin 5
//
// While the round is open, the ready LED is lit and the sketch watches all
// three answer buttons. The first one pressed wins: its LED lights, the
// buzzer beeps, and the others are ignored until reset is pressed.

const int ANSWER[3] = {2, 3, 4};
const int PLAYER_LED[3] = {6, 7, 8};
const int RESET = 9;
const int READY_LED = 10;
const int BUZZER = 5;

bool open = true;

void startRound() {
  open = true;
  for (int i = 0; i < 3; i++) digitalWrite(PLAYER_LED[i], LOW);
  digitalWrite(READY_LED, HIGH);
  Serial.println("ready: first to press wins");
}

void setup() {
  for (int i = 0; i < 3; i++) {
    pinMode(ANSWER[i], INPUT_PULLUP);
    pinMode(PLAYER_LED[i], OUTPUT);
  }
  pinMode(RESET, INPUT_PULLUP);
  pinMode(READY_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
  Serial.println("Mokxi Uno: quiz buzzer");
  startRound();
}

void loop() {
  if (open) {
    for (int i = 0; i < 3; i++) {
      if (digitalRead(ANSWER[i]) == LOW) {
        open = false;
        digitalWrite(READY_LED, LOW);
        digitalWrite(PLAYER_LED[i], HIGH);
        Serial.print("player ");
        Serial.print(i + 1);
        Serial.println(" was first");
        digitalWrite(BUZZER, HIGH);
        delay(300);
        digitalWrite(BUZZER, LOW);
        break;
      }
    }
  } else if (digitalRead(RESET) == LOW) {
    startRound();
    delay(200);
  }
}