File task

void fileInput()
{
    ifstream f_in;

    int choice3;
    string loc, line;
    printf("\nEnter File location: ");
    cin >> loc;

    f_in.open(loc.c_str());

    if (f_in.is_open())
    {
        while (getline(f_in,line))
        {
            printf("\n1. Convert to Prefix \n");
            printf("2. Convert to Postfix \n");

            printf("\nEnter your choice:");
            cin >> choice3;

            if (choice3 == 1)
            {
                prefixConverter(line);
            }
            else if (choice3 == 2)
            {
                postfixConverter(line);
            }

        }
    }
    else
    {
        std::cout << "Unable to open file" << std::endl << std::endl;
    }

    f_in.close();

    ofstream f_out;
    f_out.open(loc.c_str());

    if (choice3==1)
    {
        f_out << result1 << endl;
        cout << "Output written in File." << endl;
        result1.clear();
        result2.clear();
    }

    else if (choice3==2)
    {
        f_out << result2 << endl;
        cout << "Output written in File." << endl;
        result1.clear();
        result2.clear();
    }
    f_out.close();
}