09. Ski Trip

#include <iostream>
#include <string>

using namespace std;

int main() {
    int days;
    cin >> days;

    cin.ignore();

    string room;
    getline(cin, room);

    string rating;
    getline(cin, rating);

    int nights = days - 1;
    double roomPrice = 18.00;
    double apartmentPrice = 25.00;
    double presidentApartmentPrice = 35.00;

    double totalSum;

    if (room == "room for one person") {
        totalSum = roomPrice * nights;
    }
    else if (room == "apartment") {
        totalSum = apartmentPrice * nights;
        if (nights < 10) {
            totalSum *= 0.70;
        }
        else if (nights >= 10 && nights < 15) {
            totalSum *= 0.65;
        }
        else if (nights >= 15) {
            totalSum *= 0.50;
        }
    }
    else {
        totalSum = presidentApartmentPrice * nights;

        if (nights < 10) {
            totalSum *= 0.90;
        }
        else if (nights >= 10 && nights < 15) {
            totalSum *= 0.85;
        }
        else if (nights >= 15) {
            totalSum *= 0.80;
        }
    }

    if (rating == "positive") {
        totalSum *= 1.25;
    }
    else {
        totalSum *= 0.90;
    }

    cout.setf(ios::fixed);
    cout.precision(2);

    cout << totalSum << endl;

    return 0;
}

Решение с тернарен оператор и printf():

#include <iostream>
#include <string>

using namespace std;

int main() {
    int days;
    cin >> days;
    cin.ignore();

    string room, rating;
    getline(cin, room);
    getline(cin, rating);

    int nights = days - 1;
    double roomPricePerNight = room == "room for one person" ? 18.00 : room == "apartment" ? 25.00 : 35.00;

    double totalSum = roomPricePerNight * nights;

    totalSum *=
        room == "apartment" ? (nights < 10 ? 0.70 : nights >= 15 ? 0.50 : 0.65) :
        room == "president apartment" ? (nights < 10 ? 0.90 : nights >= 15 ? 0.80 : 0.85) : 1;

    totalSum *= rating == "positive" ? 1.25 : 0.90;

    printf("%.2f\n", totalSum);

    return 0;
}

Тарикатско решение - Don't use at work! :)

#include <iostream>
#include <string>

using namespace std;

int main() {
    string days, room, rating;
    getline(cin, days);
    getline(cin, room);
    getline(cin, rating);

    int nights = stoi(days) - 1;

    printf("%.2f\n", ((room == "room for one person" ? 18.00 :
        room == "apartment" ? 25.00 * (nights < 10 ? 0.70 : nights >= 15 ? 0.50 : 0.65) :
        35.00 * (nights < 10 ? 0.90 : nights >= 15 ? 0.80 : 0.85))
        * nights * (rating == "positive" ? 1.25 : 0.90)));

    return 0;
}