Football Souvenirs

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
    string country, souvenir;
    cin >> country >> souvenir;

    int volume;
    cin >> volume;

    string print = "";

    double sum = 0;

    if (country == "Argentina") {
        if (souvenir == "flags") {
            sum = 3.25;
        }
        else if (souvenir == "caps") {
            sum = 7.20;
        }
        else if (souvenir == "posters") {
            sum = 5.10;
        }
        else if (souvenir == "stickers") {
            sum = 1.25;
        }
        else {
            print = "Invalid stock!";
        }
    }
    else if (country == "Brazil") {
        if (souvenir == "flags") {
            sum = 4.20;
        }
        else if (souvenir == "caps") {
            sum = 8.50;
        }
        else if (souvenir == "posters") {
            sum = 5.35;
        }
        else if (souvenir == "stickers") {
            sum = 1.20;
        }
        else {
            print = "Invalid stock!";
        }
    }
    else if (country == "Croatia") {
        if (souvenir == "flags") {
            sum = 2.75;
        }
        else if (souvenir == "caps") {
            sum = 6.90;
        }
        else if (souvenir == "posters") {
            sum = 4.95;
        }
        else if (souvenir == "stickers") {
            sum = 1.10;
        }
        else {
            print = "Invalid stock!";
        }
    }
    else if (country == "Denmark") {
        if (souvenir == "flags") {
            sum = 3.10;
        }
        else if (souvenir == "caps") {
            sum = 6.50;
        }
        else if (souvenir == "posters") {
            sum = 4.80;
        }
        else if (souvenir == "stickers") {
            sum = 0.90;
        }
        else {
            print = "Invalid stock!";
        }
    }
    else {
        print = "Invalid country!";
    }

    if (sum > 0) {
        cout << "Pepi bought " << volume << " " << souvenir << " of " << country
            << " for " << fixed << setprecision(2) << sum * volume << " lv.\n";
    }
    else {
        cout << print << endl;
    }

    return 0;
}

Решение с тернарен оператор и леко тарикатската:)

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
    string country, souvenir;
    cin >> country >> souvenir;

    int volume;
    cin >> volume;

    double sum =
        country == "Argentina" ?
        (souvenir == "flags" ? 3.25 : souvenir == "caps" ? 7.20 : souvenir == "posters" ? 5.10 : souvenir == "stickers" ? 1.25 : 0) :
        country == "Brazil" ?
        (souvenir == "flags" ? 4.20 : souvenir == "caps" ? 8.50 : souvenir == "posters" ? 5.35 : souvenir == "stickers" ? 1.20 : 0) :
        country == "Croatia" ?
        (souvenir == "flags" ? 2.75 : souvenir == "caps" ? 6.90 : souvenir == "posters" ? 4.95 : souvenir == "stickers" ? 1.10 : 0) :
        country == "Denmark" ?
        (souvenir == "flags" ? 3.10 : souvenir == "caps" ? 6.50 : souvenir == "posters" ? 4.80 : souvenir == "stickers" ? 0.90 : 0) : -1;     // Ако сумата е 0 - въведена е невалидна стока, а ако е -1 - невалидна държава!

    sum > 0 ?
        cout << "Pepi bought " << volume << " " << souvenir << " of " << country << " for " << fixed << setprecision(2) << sum * volume << " lv.\n" :
        cout << (sum == 0 ? "Invalid stock!" : "Invalid country!") << endl;

    return 0;
}