#include <LiquidCrystal.h>
#include <stdio.h>
#include <stdlib.h>
#include <Keypad.h>

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

const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys[ROWS][COLS] = {
  { '1', '2', '3', 'A' },
  { '4', '5', '6', 'B' },
  { '7', '8', '9', 'C' },
  { '*', '0', '#', 'D' }
};

uint8_t colPins[COLS] = { A3, A2, A1, A0 }; // Pins connected to C1, C2, C3, C4
uint8_t rowPins[ROWS] = { 5, 4, 3, 2 }; // Pins connected to R1, R2, R3, R4

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);


int main() {
  int n;
  double *data;
  printf("Enter the total number of elements: ");
  scanf("%d", &n);
 
  // Allocating memory for n elements
  data = (double *)calloc(n, sizeof(double));
  if (data == NULL) {
  printf("Error!!! memory not allocated.");
  exit(0);
  }
 
  // Storing numbers entered by the user.
  for (int i = 0; i < n; ++i) {
  printf("Enter number%d: ", i + 1);
  scanf("%lf", data + i);
  }
 
  // Finding the largest number
  for (int i = 1; i < n; ++i) {
    if (*data < *(data + i)) {
      *data = *(data + i);
    }
  }
  printf("Largest number = %.2lf", *data);
 
  free(data);
 
  return 0;
}
void setup() {
  Serial.begin(9600);
}

void loop() {
  char key = keypad.getKey();

  if (key != NO_KEY) {
    Serial.println(key);
  }
}