// This program reads a file of students' attendance in section
// (a 1 means a student attended, a 0 means they did not) and
// uses arrays to compute attendance points and grade percentages.
//
// Each line of input represents one section and each 5 characters
// on a line represent the 5 students in the section.
//
// This version has better decomposition into methods and reports
// the results to an output file.

import java.io.*;
import java.util.*;

public class Sections2 {
    public static final int STUDENTS = 5;   // # of students/section

    public static void main(String[] args) throws FileNotFoundException {
        Scanner input = new Scanner(new File("sections.txt"));
        PrintStream stream = new PrintStream(new File("grades.txt"));

        int count = 1;
        while (input.hasNextLine()) {
            String line = input.nextLine();  // "111111101011111101001110110110110001110010100"
            int[] attended = section(line, count);
            int[] points = sectionPoints(attended);
            double[] grades = sectionPercentages(points);
            results(stream, count, attended, points, grades);
            count++;
        }
    }
    
    // This method processes a single section line from the file.
    public static int[] section(String line, int number) {
        int[] attended = new int[STUDENTS];   // [0, 0, 0, 0, 0]
        for (int i = 0; i < line.length(); i++) {
            char c = line.charAt(i);  // '1' or '0'
            // i       0 1 2 3 4 5 6 7 8 9 10 11 ...
            // student 0 1 2 3 4 0 1 2 3 4  0  1 ...
            // expression to connect them: i % 5
            int student = i % STUDENTS;
            if (c == '1') {
                attended[student]++;
            }
        }

        // sectionGrades(attended);
        return attended;
    }

    // This method accepts the array for the number of sections attended
    // as a parameter and computes the students' section points.
    public static int[] sectionPoints(int[] attended) {
        // compute section points from # sections attended
        int[] points = new int[STUDENTS];
        for (int i = 0; i < STUDENTS; i++) {
            points[i] = Math.min(20, attended[i] * 3);
        }
        return points;
    }
    
    // Computes the section grades from the points earned.
    public static double[] sectionPercentages(int[] points) {
        double[] grades = new double[STUDENTS];
        for (int i = 0; i < STUDENTS; i++) {
            grades[i] = points[i] / 20.0 * 100;
        }
        return grades;
    }
    
    // Reports the results to the output file.
    public static void results(PrintStream stream, int number, int[] attended, 
                               int[] points, double[] grades) {
        stream.println("Section " + number + ":");
        stream.println(Arrays.toString(attended));
        stream.println(Arrays.toString(points));
        stream.println(Arrays.toString(grades));
    }
}