#include <Keypad.h>
#include <Wire.h> // Include the Wire library for I2C communication
#include <LiquidCrystal_I2C.h>
#include <vector>

const int ROW_NUM = 4; // Four rows
const int COLUMN_NUM = 4; // Four columns

char keys[ROW_NUM][COLUMN_NUM] = {
    {'1', '2', '3', 'A'},
    {'4', '5', '6', 'B'},
    {'7', '8', '9', 'C'},
    {'*', '0', '#', 'D'}
};

byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; // Connect to the row pinouts of the keypad
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM);
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 columns and 2 rows

int cursorColumn = 0;

void setup() {
    lcd.init(); // Initialize the LCD
    lcd.backlight();
}

void loop() {
    char key = keypad.getKey();
    if (key) {
        lcd.setCursor(cursorColumn, 0); // Move cursor to (cursorColumn, 0)
        lcd.print(key); // Print key at (cursorColumn, 0)
        cursorColumn++; // Move cursor to the next position
        if (cursorColumn == 16) {
            // If reaching the limit, clear the LCD
            lcd.clear();
            cursorColumn = 0;
        }
    }

    // Your main loop code can go here
    // For example, you can call functions like simplifyExpression() or decimalToBinary()
    // and use the keypad input for your calculations.
}