C ++ 10的大數冪

Question

C ++編程的新手。 有沒有一種方法可以使代碼更好，從而避免重復的代碼。

if (totalDistance < pow(10, 3)) {
    cout << "\nTotal (approx) travel distance = " << totalDistance << " million km\n" << endl;
}
else if (totalDistance < pow(10, 6)) {
    totalDistance = totalDistance / pow(10, 3);
    cout << "\nTotal (approx) travel distance = " << totalDistance << " billion km\n" << endl;
}
else if (totalDistance < pow(10, 9)) {
    totalDistance = totalDistance / pow(10, 6);
    cout << "\nTotal (approx) travel distance = " << totalDistance << " trillion km\n" << endl;
}

Answer 1

cout << "\nTotal (approx) travel distance = ";
if (totalDistance < pow(10, 3)) {
    cout << totalDistance << " million km\n";
else if (totalDistance < pow(10, 6)) {
    cout << totalDistance / pow(10, 3) << " billion km\n";
}else if (totalDistance < pow(10, 9)) {
    cout << totalDistance / pwo(10, 6) << " trillion km\n";
}

我假設您不再使用totalDistance，並且如果您已經在使用'\\ n'，則不需要endl。

Answer 2

最簡單的改進：

if (totalDistance < pow(10, 3)) {
    outputDistance(totalDistance); 
}
else if (totalDistance < pow(10, 6)) {
    totalDistance = totalDistance / pow(10, 3);
    outputDistance(totalDistance); 
}
else if (totalDistance < pow(10, 9)) {
    totalDistance = totalDistance / pow(10, 6);
    outputDistance(totalDistance); 
}

private void outputDistance(const double totalDistance) {
cout << "\nTotal (approx) travel distance = " << totalDistance << " trillion km\n" << endl;
}