04. Grades

#include <iostream>

using namespace std;

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

    double grade3 = 0, grade4 = 0, grade5 = 0, grade6 = 0, totalGradeSum = 0, currentGrade;

    for (int i = 0; i < studentCount; i++) {
        cin >> currentGrade;

        if (currentGrade >= 5) {
            grade6++;
        }
        else if (currentGrade >= 4) {
            grade5++;
        }
        else if (currentGrade >= 3) {
            grade4++;
        }
        else if (currentGrade >= 2) {
            grade3++;
        }

        totalGradeSum += currentGrade;
    }
    cout.setf(ios::fixed);
    cout.precision(2);

    cout << "Top students: " << 100.0 * grade6 / studentCount << "%\n";
    cout << "Between 4.00 and 4.99: " << 100.0 * grade5 / studentCount << "%\n";
    cout << "Between 3.00 and 3.99: " << 100.0 * grade4 / studentCount << "%\n";
    cout << "Fail: " << 100.0 * grade3 / studentCount << "%\n";
    cout << "Average: " << 1.0 * totalGradeSum / studentCount << endl;

    return 0;
}

Решение с тернарен оператор:

#include <iostream>

using namespace std;

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

    double grade3 = 0, grade4 = 0, grade5 = 0, grade6 = 0, totalGradeSum = 0, currentGrade;

    for (int i = 0; i < studentCount; i++) {
        cin >> currentGrade;

        currentGrade >= 5 ? grade6++ : currentGrade >= 4 ? grade5++ : currentGrade >= 3 ? grade4++ : grade3++;

        totalGradeSum += currentGrade;
    }

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

    cout << "Top students: " << 100.0 * grade6 / studentCount << "%\n";
    cout << "Between 4.00 and 4.99: " << 100.0 * grade5 / studentCount << "%\n";
    cout << "Between 3.00 and 3.99: " << 100.0 * grade4 / studentCount << "%\n";
    cout << "Fail: " << 100.0 * grade3 / studentCount << "%\n";
    cout << "Average: " << 1.0 * totalGradeSum / studentCount << endl;

    return 0;
}