Вывести числа в обратном порядке и определить сумму чисел

#include <iostream>
#include <numeric>
#include <algorithm>
#include <iterator>
 
int main() {
  const size_t size      = 5;
        double arr[size] = { 5.0, 4.0, 3.0, 2.0, 1.0 };
 
  std::cout << "Array: ";
  std::copy(arr, arr + size, std::ostream_iterator<double>(std::cout, " "));
  std::cout << std::endl;
 
  std::cout << "Sum: " << std::accumulate(arr, arr + size, 0.0) << std::endl;
 
  std::cout << "Reverse array: ";
  std::reverse_copy(arr, arr + size, std::ostream_iterator<double>(std::cout, " "));
  std:cout << std::endl;
 
  return 0;
}

#include <iostream>
#include <numeric>
#include <algorithm>
#include <iterator>
 
int main() {
  const size_t size      = 25;
  double arr[size];
  int i;
 
for(i = 0; i <= size; i++)
{
    std::cout << "el massiva №" << i << std::endl;
    std::cin >> arr[i];
}
    
  std::cout << "Array: ";
  std::copy(arr, arr + size, std::ostream_iterator<double>(std::cout, " "));
  std::cout << std::endl;
 
  std::cout << "Sum: " << std::accumulate(arr, arr + size, 0.0) << std::endl;
 
  std::cout << "Reverse array: ";
  std::reverse_copy(arr, arr + size, std::ostream_iterator<double>(std::cout, " "));
  std::cout << std::endl;
  return 0;
}