// Name:    Choi Ka Ho
// No.:     240021155
// Class:   EG114403/1D
// Program: Ex5_Array.ino

char buf[100] = {0};  //Enter a maximum of 100 bytes
char inChar;
bool stringComplete = false;
int i = 0;

char ConvertChar(char);

void setup()
{
  Serial.begin(115200);
}

void loop() {
  int num;
  while (Serial.available())
  {
    // (char)Serial.read(); The previously defined inChar
    inChar = Serial.read();            //can not be proved here

    if (inChar == '\n')
    {
      buf[i++] = inChar;
      buf[i] = 0;
      stringComplete = true;
    }
    else
    {
      inChar = ConvertChar(inChar);
      buf[i++] = inChar;
    }
  }

  if (stringComplete) { //Nested loop
    if ((i == 2) && (isDigit(buf[0]))) {   //Control units digit
      num = buf[0] - '0';
      PrintStars(num); //Input star'*'
    } else {
      if ((i == 3) && (isDigit(buf[0])) && (isDigit(buf[1]))) {
        num = (((buf[0] - '0' ) * 10) + (buf[1] - '0'));
        PrintStars(num);                  //Control two digit
      } else {
        Serial.println("Incorrect input");  //If it's another input
        Serial.println();
      }
    }

    stringComplete = false;  //After each input
    i = 0;  //Restore basic step
    num = 0;
  }
}

void PrintStars(int n) {
  for (int j = 0; j < n; j++) {
    Serial.print('*');
    if ((j + 1) % 10 == 0) { //every 10 stars, go to a new line
      Serial.println();
    }
  }
  Serial.println();
}
char ConvertChar(char x)
{
  // if((x >= 65) && (x <= 90))
  if ((x >= 'A') && (x <= 'Z'))
    return (x + 32);
  else if (isLowerCase(x))
    return (toUpperCase(x));
  else
    return (x);
}