package OAiP;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;
import java.util.Scanner;


public class Program2 {

    public static void main(String[] args) throws FileNotFoundException {
        saveMatrixToFile("output.txt");
        int[][] studentMarks = loadMatrixFromFile("student_marks.txt");

        int[] negativeStudentMarks = new int[30];
        for (int i = 0; i < 30; i++) {
            negativeStudentMarks[i] = countNegativeMarks(studentMarks[i]);
        }

        for (int i = 0; i < 30; i++) {
            System.out.print(String.format("Студент N%2d:", (i + 1)));
            for (int j = 0; j < 10; ++j) {
                System.out.print(String.format("%3d", studentMarks[i][j]));
            }
            System.out.println(String.format(" : негативных оценок = %d", negativeStudentMarks[i]));
        }
    }

    private static void saveMatrixToFile(String path) {
        Random random = new Random();
        try {
            BufferedWriter output = new BufferedWriter(new FileWriter(path));

            for (int i = 0; i < 30; ++i) {
                for (int j = 0; j < 10; ++j) {
                    int mark = random.nextInt(10) + 1;
                    output.write(String.format("%3d", mark));
                }
                output.newLine();
            }

            output.flush();
            output.close();
        } catch (IOException e) {
            System.out.println("Ошибка ввода/вывода!");
        }
    }

    private static int[][] loadMatrixFromFile(String path) throws FileNotFoundException {
        Scanner input = new Scanner(new File(path));

        int[][] result = new int[30][10];

        for (int i = 0; i < 30; ++i) {
            for (int j = 0; j < 10; ++j) {
                if (input.hasNextInt()) {
                    result[i][j] = input.nextInt();
                }
            }
        }

        input.close();

        return result;
    }

    private static int countNegativeMarks(int[] marks) {
        int count = 0;

        for (int i = 0; i < 10; i++) {
            if (marks[i] < 4) {
                count++;
            }
        }

        return count;
    }
}