ex4_22.cpp

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
    unsigned grade;
    while (cin >> grade) {
        // first version(only use conditional operators)
        cout << ((grade > 90) ? "high pass" : (grade < 60)
                                                  ? "fail"
                                                  : (grade < 75) ? "low pass"
                                                                 : "pass");
        cout << endl;
        // second version(only use if statements)
        if (grade > 90)
            cout << "high pass";
        else if (grade < 60)
            cout << "fail";
        else if (grade < 75)
            cout << "low pass";
        else
            cout << "pass";
        cout << endl;
    }

    return 0;
}