Family Trip

#include <iostream>
#include <string>

using namespace std;

int main() {
    double budget;
    cin >> budget;

    int overnights;
    cin >> overnights;

    double overnightPrice;
    cin >> overnightPrice;

    int additionalCosts;
    cin >> additionalCosts;

    if (overnights > 7) {
        overnightPrice *= 0.95;
    }

    budget -= overnightPrice * overnights + 0.01 * budget * additionalCosts;

    if (budget >= 0) {
        printf("Ivanovi will be left with %.2f leva after vacation.\n", budget);
    }
    else {
        printf("%.2f leva needed.\n", abs(budget));
    }
    return 0;
}

Решение с тернарен оператор и леко тарикатската:)

#include <iostream>
#include <string>

using namespace std;

int main() {
    double budget, overnights, overnightPrice, additionalCosts;
    cin >> budget >> overnights >> overnightPrice >> additionalCosts;

    budget -= overnightPrice * (overnights > 7 ? 0.95 : 1) * overnights + 0.01 * budget * additionalCosts;

    budget >= 0 ?
        printf("Ivanovi will be left with %.2f leva after vacation.\n", budget) :
        printf("%.2f leva needed.\n", abs(budget));

    return 0;
}