// 10 задание
int buttonState = 0;      
int lastButtonState = HIGH;  
int mode = 1;                
unsigned long lastDebounceTime = 0; 
unsigned long previousMillis = 0; 
const long interval = 500;        
bool ledBlinkState = LOW;         
void setup() {
  pinMode(13, OUTPUT);
  pinMode(2, INPUT_PULLUP); 
}
void loop() {
  int reading = digitalRead(2);
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }
  if ((millis() - lastDebounceTime) > 50) {
    if (reading != buttonState) {
      buttonState = reading;
      if (buttonState == LOW) {
        mode++;
        if (mode > 4) {
          mode = 1;
        }
        digitalWrite(13, LOW);
      }
    }
  }
  lastButtonState = reading; 
  switch (mode) {
    case 1:
      digitalWrite(13, LOW);
      break;
    case 2:
      {
        int ldrValue = analogRead(A0);
        int brightness = map(ldrValue, 0, 1023, 255, 0);
        brightness = constrain(brightness, 0, 255);
        analogWrite(13, brightness);
      }
      break;
    case 3:
      {
        unsigned long currentMillis = millis();
        if (currentMillis - previousMillis >= interval) {
          previousMillis = currentMillis;
          ledBlinkState = !ledBlinkState;
          digitalWrite(13, ledBlinkState);
        }
      }
      break;
    case 4:
      digitalWrite(13, HIGH);
      break;
  }
  delay(10);
}