A GPA Calculator for HUST

gpacalc.cpp

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

using namespace std;

inline double ToDouble(const string &sOrg)
try {
    return stod(sOrg);
}
catch(...) {
    return 0.0;
}

int main() {
    cout << "This program ignores courses whose mark is less than 60." << endl;
    string sName, sMark, sCred;
    auto dSumMark = 0.0;
    auto dSumGrad = 0.0;
    auto dSumCred = 0.0;
    auto nCourses = 0;
    while (cin >> sName >> sMark >> sCred) {
        auto dMark = ToDouble(sMark);
        auto dCred = ToDouble(sCred);
        auto dGrad = dMark > 85.0 - 1.0e-12 ? 4.0 :
            dMark > 60.0 - 1.0e-12 ? 1.5 + (dMark - 60.0) * 0.1 : 0.0;
        if (dMark > 60.0 - 1.0e-12) {
            ++nCourses;
            dSumMark += dMark * dCred;
            dSumGrad += dGrad * dCred;
            dSumCred += dCred;
            cout << left << setw(48) << sName;
            cout << left << setw(8) << fixed << setprecision(2) << dMark;
            cout << left << setw(8) << fixed << setprecision(1) << dGrad;
            cout << left << setw(8) << fixed << setprecision(1) << dCred;
            cout << endl;
        }
    }
    cout << "Summary:" << endl;
    cout << "    Total Courses : " << nCourses << endl;
    cout << "    Total Marks   : " << fixed << setprecision(2) << dSumMark << endl;
    cout << "    Total Grades  : " << fixed << setprecision(1) << dSumGrad << endl;
    cout << "    Total Credits : " << fixed << setprecision(1) << dSumCred << endl;
    cout << "    Average Marks : " << fixed << setprecision(2) << dSumMark / dSumCred << endl;
    cout << "    GPA           : " << fixed << setprecision(6) << dSumGrad / dSumCred << endl;
    return 0;
}