/*
6. Write a program to read a file of ints. Save every other int into
   an array, starting with the first one. Assume that there are no
   more than 10000 ints in the file (but you don't know how many).
   Find the average of the ints that you scanned and return that number.
*/

#include<fstream>
#include<iostream>
#include<cstdlib>
using namespace std;

float averageOfEveryOfInt(const string& filename, int []);

int main()
{
    int array[5000];
    cout << averageOfEveryOfInt("int10000.txt",array) << endl;
}

float averageOfEveryOfInt(const string& filename, int a[])
{
    ifstream fin(filename);
    if (!fin)
    {
        cerr << "Cannot open " << filename << endl;
        exit(1);
    }
    int sum = 0;
    int loopcount = 0;
    int index = 0;
    int num;
    while (fin >> num)
    {
        loopcount++;
        // process only odd numbered values
        if (loopcount % 2 == 1)
        {
            a[index] = num;     // store the value into the array
            index++;           // increment array index
            sum += num;         // cumulate the value
        }
    }
    // return the average
    return static_cast<float>(sum)/index;
}