03-00.cpp

#include <iostream>
#include <iomanip>
#include <ios>
#include <string>

using namespace std;

int main()
{
    cout << "Please, enter your name: ";
    string name;
    cin >> name;
    cout << "Hello, " << name << "!" << endl;

    cout << "Please enter your midterm and final exam grades: ";
    double midterm, final;
    cin >> midterm >> final;

    cout << "Enter all your homework grades, "
        "followed by end-of-file: ";

    int count = 0;
    double sum = 0;
    double x;
    while( cin >> x ) {
        ++count;
        sum += x;
    }

    double final_grade = 0.2 * midterm + 0.4 * final;
    if(count > 0) {
        final_grade += 0.4 * sum / count;
    } else {
        cerr << "Bad data in input" << endl;
        return 1;
    }

    streamsize prec = cout.precision();
    cout << "Your final grade is " << setprecision(3)
        << final_grade
        << setprecision(prec) << endl;
    cout << "Precision was " << prec << endl;

    return 0;
}