// TEAM 2 - ACTIVITY 3 - PROCEDURE
// COMPUTE THE HIGHEST NUMBER IN THE INPUT ELEMENTS


#include <LiquidCrystal.h>
#include <Keypad.h>
#include <Servo.h>

/* Display */
LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {5, 4, 3, 2};
byte colPins[KEYPAD_COLS] = {A3, A2, A1, A0};
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', '+'},
  {'4', '5', '6', '-'},
  {'7', '8', '9', '*'},
  {'.', '0', '=', '/'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);

void setup() {
  Serial.begin(115200);
  lcd.begin(16, 2);
  lcd.setCursor(0, 0); // set cursor at (c,r)
}

void loop() {
    // dynamically allocate array with size n
  double *data;
  lcd.print("NO. OF ELEMENTS:"); //printf("Enter the total number of elements: ");
  lcd.setCursor(0, 1); 
  char key = NULL;
  String elements = "";
  String inputElements = "";
  int n;
  while (key != '=') { // equals ('=') key used as enter key (changed to ✔)
    key = keypad.getKey();
    if (key >= '0' && key <= '9') //only act on numeric keys
    {
      lcd.print(key);
      elements += key;
    }
  }
  n = elements.toDouble(); // convert number of elements to double
  delay(1000);
  lcd.clear();

  // Allocating memory for n elements
  data = (double *)calloc(n, sizeof(double));

  // Storing elements
  for (int i = 0; i < n; ++i) {
    lcd.setCursor(0, 0);
    lcd.print("ELEMENTS(" + String(n) + "):");
    lcd.setCursor(0, 1);
    key = NULL;
    while (key != '=') { // equals ('=') key used as enter key (changed to ✔)
      key = keypad.getKey();
      if (key >= '0' && key <= '9' || key == '.') {
        inputElements += key;
        lcd.print(key);
      }
    }
    data[i] = inputElements.toDouble();
    inputElements = "";
    lcd.clear();  
    }

  delay(1000);
  lcd.clear();
  lcd.setCursor(0, 0);

  lcd.print("HIGHEST:");
  lcd.setCursor(0, 1);
  // Computing the largest number
  for (int i = 1; i < n; ++i) {
    if (*data < *(data + i)) {
      *data = *(data + i);
    }
  }
  lcd.print(*data);
  while (true) {
    continue;
  }
}