Fitness Center

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

int main()
{
    int visitors,
        back = 0,
        chest = 0,
        legs = 0,
        abs = 0,
        proteinBar = 0,
        proteinShake = 0;
    cin >> visitors;
    cin.ignore();

    string action;

    for (int i = 0; i < visitors; i++) {
        getline(cin, action);
        if (action == "Back") {
            back++;
        }
        else if (action == "Chest") {
            chest++;
        }
        else if (action == "Legs") {
            legs++;
        }
        else if (action == "Abs") {
            abs++;
        }
        else if (action == "Protein bar") {
            proteinBar++;
        }
        else {
            proteinShake++;
        }
    }

    cout << back << " - back\n"
        << chest << " - chest\n"
        << legs << " - legs\n"
        << abs << " - abs\n"
        << proteinShake << " - protein shake\n"
        << proteinBar << " - protein bar\n"
        << fixed << setprecision(2)
        << 100.0 * (back + chest + legs + abs) / visitors << "% - work out\n"
        << 100.0 * (proteinShake + proteinBar) / visitors << "% - protein\n";

    return 0;
}

Решение с тернарен оператор:

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

int main()
{
    int visitors,
        back = 0,
        chest = 0,
        legs = 0,
        abs = 0,
        proteinBar = 0,
        proteinShake = 0;
    cin >> visitors;
    cin.ignore();

    string action;

    for (int i = 0; i < visitors; i++) {
        getline(cin, action);

        action == "Back" ? back++ :
            action == "Chest" ? chest++ :
            action == "Legs" ? legs++ :
            action == "Abs" ? abs++ :
            action == "Protein bar" ? proteinBar++ : proteinShake++;
    }

    cout << back << " - back\n"
        << chest << " - chest\n"
        << legs << " - legs\n"
        << abs << " - abs\n"
        << proteinShake << " - protein shake\n"
        << proteinBar << " - protein bar\n"
        << fixed << setprecision(2)
        << 100.0 * (back + chest + legs + abs) / visitors << "% - work out\n"
        << 100.0 * (proteinShake + proteinBar) / visitors << "% - protein\n";

    return 0;
}