CalculateGradesStatisticsSolution.java

public class CalculateGradesStatisticsSolution {

    private static void calculateGradesStatistics(int[] grades) {
        int countA = 0, countB = 0, countC = 0, countD = 0, countF = 0;

        for (int grade : grades) {
            switch (grade / 10) {
                case 10, 9:
                    countA++;
                    break;
                case 8:
                    countB++;
                    break;
                case 7:
                    countC++;
                    break;
                case 6:
                    countD++;
                    break;
                default:
                    countF++;
                    break;
            }
        }

        System.out.println("A: " + countA + "\n"
                + "B: " + countB + "\n"
                + "C: " + countC + "\n"
                + "D: " + countD + "\n"
                + "F: " + countF);
    }

}