Заменить каждый элемент массива на среднее арифметическое элемента и его соседей

#include <iostream>
#include <cstdlib>
 
int main()
{
    unsigned int size;
    std::cout << "Enter the size of sequence" << std::endl;
    std::cin >> size;
    
    double* vector = new double[size];
    std::cout << "Enter the sequence" << std::endl;
    for (unsigned int i = 0; i < size; ++i)
        std::cin >> vector[i];
    for (unsigned int i = 1; i < (size - 1); ++i)
        vector[i] = (vector[i - 1] + vector[i + 1]) / 2;
    std::cout << "Answer: " << std::endl;
    for (unsigned int i = 0; i < size; ++i)
        std::cout << vector[i] << " ";
    std::cout << std::endl;
    delete[]vector;
    return EXIT_SUCCESS;
}

vector[i] = (vector[i - 1] + vector[i + 1] + vector[i]) / 3;

#include <iostream>
#include <cstdlib>
 
int main()
{
    unsigned int size;
    std::cout << "Enter the size of sequence" << std::endl;
    std::cin >> size;
    
    double* vector = new double[size];
    double* result_vector = new double[size];
    std::cout << "Enter the sequence" << std::endl;
    for (unsigned int i = 0; i < size; ++i)
        std::cin >> vector[i];
    result_vector[0] = vector[0];
    result_vector[size - 1] = vector[size - 1];
    for (unsigned int i = 1; i < (size - 1); ++i)
        result_vector[i] = (vector[i - 1] + vector[i + 1] + vector[i]) / 2;
    std::cout << "Answer: " << std::endl;
    std::swap(result_vector, vector);
    for (unsigned int i = 0; i < size; ++i)
        std::cout << vector[i] << " ";
    std::cout << std::endl;
    delete[]vector;
    delete[]result_vector;
    return EXIT_SUCCESS;
}

#include <iostream>
 
using namespace std;
 
int main()
{
    const int n = 10;
    double initialArray[n] = {2, -1, 5, -3, 0, 5, 6, 9, -1, 8};
    cout << "Array before:" << '\n';
    for (int i = 0; i < n; i++)
    {
        cout << initialArray[i] << "  ";
    }
 
    double tempArray[n];
    tempArray[0] = (initialArray[0] + initialArray[1]) / 2;
    for (int i = 1; i < n - 1; i++)
    {
        tempArray[i] = (initialArray[i - 1] + initialArray[i] + initialArray[i + 1]) / 3;
    }
    tempArray[n - 1] = (initialArray[n - 1] + initialArray[n - 2]) / 2;
    for (int i = 0; i < n; i++)
    {
        initialArray[i] = tempArray[i];
    }
 
    cout << "Array after:" << '\n';
    for (int i = 0; i < n; i++)
    {
        cout << initialArray[i] << "  ";
    }
 
    cout << '\n';
    return 0;
}