//Malrechentabellenprinter © 2024 by Nathanael Nürk is licensed under CC BY-NC-SA 4.0 
void bars(int maximum = 10, String barCharacter = "-"){
  Serial.print(barCharacter);
  if(maximum >= 10){
    Serial.print(barCharacter);
  }
  if(maximum >= 100){
    Serial.print(barCharacter);
  }
  if(maximum >= 1000){
    Serial.print(barCharacter);
  }
  if(maximum >= 10000){
    Serial.print(barCharacter);
  }
}

void barLayout(int maximum = 10, byte ranges = 10){
  bars(maximum);
  for(byte x = 0;x<= ranges ; x++){
    Serial.print("+");
    bars(maximum);
  }
  Serial.println("+");
}



void layout(int Number, int maximum = 0){
  if(Number < 1000 and maximum>= 1000){
    Serial.print(" ");
  }
  if(Number < 10  and maximum >= 10){
    Serial.print(" ");
  }
  Serial.print(Number);
  if(Number < 100  and maximum >= 100){
    Serial.print(" ");
  }
  if(Number < 10000 and maximum >= 10000){
    Serial.print(" ");
  }
}

void tableprinter(byte startx = 0,byte starty =0,byte range =10){
  int maximum = (startx+range)*(starty+range);
  Serial.println("Table from "+String(startx) +"*"+String(starty)+" to " + String(startx +10)+"*"+String(starty+10)+"\n");
  bars(maximum," ");
  Serial.print("|");
  for(byte first = 0; first <= range ; first++){
      layout(first+startx,maximum);
      Serial.print("|");
  }
  Serial.println("");
  for(byte y = 0; y <= range;y++){      
      
      barLayout(maximum,range);
      
      layout(y+starty,maximum);
      Serial.print("|");
      for(byte x = 0; x <= range; x++){
          layout((x+startx)*(y+starty),maximum);
          Serial.print("|");
      }
      Serial.println("");
      
  }
  Serial.println("");
}

void setup() {
  Serial.begin(115200);
  Serial.println("\n\n\nReady to print vour Muliplication table.");
  Serial.println("Press the Buttons for following action:\nRed for (0 to 10)*(0 to 10) \nGreen for (10 to 20)*(10 to 20)\nBlue for (20 to 30)*(20 to 30)\nYellow for (30 to 40)*(30 to 40)");
  pinMode(2, INPUT_PULLUP);//Roter Knopf
  pinMode(3, INPUT_PULLUP);//Grüner Knopf
  pinMode(4, INPUT_PULLUP);//Blauer Knopf
  pinMode(5, INPUT_PULLUP);//Gelber Knopf
  while(not(digitalRead(2) and digitalRead(3) and digitalRead(4))){
    delay(5);
  }
  
}

void loop() {
  byte lowpn = getlowpin();
  if(lowpn != 0){
      int startmx = -10;
      while(lowpn != 0){
          startmx += 10;
          lowpn--;
      }
      tableprinter(startmx,startmx,10);
  }
  delay(10);
}

byte getlowpin(){
  int lowpin =0;
  for(int i = 2; i<6;i++){  //edit i < (Pins);
    if(digitalRead(i)==LOW){
      lowpin=i;
      delay(100);
      //Serial.print("lowpin: ");
      //Serial.println(lowpin);
      continue;
    }
  }
  lowpin--;
  if(lowpin <= 0){
    lowpin = 0;
  }
  //Serial.print("Lowpin ist Jetzt");
  //Serial.println( lowpin);
  return lowpin;
}