Dev - C++ - Ejercico vectores con promedio

#include <iostream>

using namespace std;

int main ()

{

    int a[5], b[9];

    cout << "\nVector A:\n";

    for(int i = 0; i < 5; i++) {

        cout << "(" << i + 1 << "): ";

        cin >> a[i];

    }

    int anterior = a[0], promedio = 0, k = 1;

    b[0] = anterior;

    for(int i = 1; i < 5; i++) {

        promedio = (anterior + a[i]) / 2;

        b[k++] = promedio;

        b[k++] = a[i];

        anterior = a[i];

    }

    cout << "\nVector B: ";

    for(int i = 0; i < 9; i++)

        cout << b[i] << " ";

    cout << endl;

    return 0;

}