C ++大数10的幂

Question

C ++编程新手。有没有办法使代码更好，以便它没有重复的代码。

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";
}

我假设您不再使用totalDistance，如果您已经在使用＆＃39; \ n＆＃39;

，则不需要endl。

Answer 2

最简单的改进：

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;
}