class LEDBlinker { 
  public: LEDBlinker(int ledpin, int onInterval, int offInterval) { 
    pin = ledpin; 
    state = LOW; 
    previousTime = 0; 
    onInt = onInterval; 
    offInt = offInterval; 
    blinking = true; 
    pinMode(pin, OUTPUT); 
  } 
void update() { 
  if (!blinking) return; 
  unsigned long currentTime = millis(); 
  if ((state == HIGH) && (currentTime - previousTime >= onInt)) { 
    previousTime = currentTime; 
    state = LOW; 
    digitalWrite(pin, state); 
    } else if ((state == LOW) && (currentTime - previousTime >= offInt)) { 
      previousTime = currentTime; 
      state = HIGH; 
      digitalWrite(pin, state); 
      } 
} 

void stopBlink() { 
  blinking = false; 
  digitalWrite(pin, LOW); 
  } 

void startBlink() { 
blinking = true; 
previousTime = millis(); 
} 

bool isBlinking() { 
  return blinking; 
} 

private: int pin; 
int onInt; 
int offInt; 
int state; 
unsigned long previousTime; 
bool blinking; 
};

const int LED_PINS[5] = {12, 11, 10, 9, 8}; 
LEDBlinker leds[5] = { 
  LEDBlinker(12, 500, 500), 
  LEDBlinker(11, 1000, 500), 
  LEDBlinker(10, 200, 200), 
  LEDBlinker(9, 700, 300), 
  LEDBlinker(8, 300, 300) 
  }; 
  
void setup() { 
  Serial.begin(9600); 
} 

void loop() { 
  for (int i = 0; i < 5; i++) { 
    leds[i].update(); 
} 
if (Serial.available()) { 
  char ch = Serial.read(); 
  if (ch == ' ') { 
    bool anyBlinking = false; 
    for (int i = 0; i < 5; i++) { 
      if (leds[i].isBlinking()) { 
        anyBlinking = true; break; 
        } 
} 

if (anyBlinking) { 
  for (int i = 0; i < 5; i++) { 
    leds[i].stopBlink(); 
    } Serial.println("All LEDs stopped blinking."); 
    } else { 
      for (int i = 0; i < 5; i++) { 
        leds[i].startBlink(); 
} 
Serial.println("All LEDs started blinking."); 
} 
} else if (ch >= '1' && ch <= '5') { 
  int ledIndex = ch - '1'; 
  if (leds[ledIndex].isBlinking()) { 
    leds[ledIndex].stopBlink(); 
    Serial.print("LED "); 
    Serial.print(ledIndex + 1); 
    Serial.println(" stopped blinking.");
     } else { 
      leds[ledIndex].startBlink(); 
      Serial.print("LED "); 
      Serial.print(ledIndex + 1); 
      Serial.println(" started blinking."); 
      } 
    } 
  } 
}