import java.util.*;

public class ExamSchedule {
        // Variable declaration that will satisfy the exam schedule
        int[][] adjacency_matrix;
        int[] exam_days, degrs;
        int num_courses, Days;
        ArrayList exam_schedule = new ArrayList();

        // Array is initialized
        public ExamSchedule(int size, int[][] adjacency_matrix) {
                this.num_courses = size;
                this.exam_days = new int[size];
                this.degrs = new int [size];
                this.adjacency_matrix = new int [size][size];
                this.adjacency_matrix = adjacency_matrix;

                for (int i = 0; i < size;i++){
                        degrs[i] = 0;
                        for (int j = 0; j < size;j++){
                                degrs[i] = degrs[i] + adjacency_matrix[i][j];
                        }
                }
        }
        // Method to generate exam schedule, and save everything into designated variable
        public void CreateSchedule() {
                boolean[] done = new boolean[num_courses];
                boolean no_con = false;
                int days = 0;
                int size;
                for (int i = 0; i < num_courses; i++) {
                        done[i] = false;
                }
                // Counted for loop that will add to the array list with exam info
                for (int i = 0; i < num_courses; i++) {
                        if (!done[i]) {
                                days++;
                                exam_schedule.add(new ArrayList());
                                ((ArrayList) exam_schedule.get(days - 1)).add(i);
                                exam_days[i] = days;
                                done[i] = true;
                        }
                        for (int j = 0; j < num_courses; j++) {
                                no_con = true;
                                size = ((ArrayList) exam_schedule.get(days - 1)).size();
                                if (adjacency_matrix[i][j] == 0) {
                                        if (size >= 1) {
                // This for loop will go through the exams and check for conflicts
                                                for (int k = 1; k < size; k++) {
                                                        if ((adjacency_matrix[((Integer) ((ArrayList) (exam_schedule
                                                                        .get(days - 1))).get(k))][j]) == 1) {
                                                                no_con = false;
                                                        }
                                                }
                // if no conflicts are found then this selection statement will run
                                                if (no_con) {
                                                        ((ArrayList) exam_schedule.get(days - 1)).add(j);
                                                        done[j] = true;
                                                        exam_days[j] = days;
                                                }
                                        }
                                }
                        }
           // Resizes adjacency matrix
                        for (int j = 0; j < ((ArrayList) exam_schedule.get(days - 1)).size(); j++) {
                                // Convert all 0's to 1's for rows and columns of used exams.
                                for (int k = 0; k < num_courses; k++) {
                                        adjacency_matrix[(Integer) (((ArrayList) exam_schedule.get(days - 1))
                                                        .get(j))][k] = 1;
                                        adjacency_matrix[k][(Integer) (((ArrayList) exam_schedule.get(days - 1))
                                                        .get(j))] = 1;
                                }
                        }
                }
                //Includes left over exams on their own days.
                for (int i = 0; i < num_courses; i++) {
                        if (!done[i]) {
                                days++;
                                exam_schedule.add(new ArrayList());
                                ((ArrayList) exam_schedule.get(days - 1)).add(i);
                        }
                }
                //Stores the total number of days used.
                Days = days;
        }
        //Gives the number of days of exams
        public int howManyDays() {
                return Days;
        }
        //Exam schedule is returned based on the course
        public int[] whatDays() {
                return exam_days;
        }
        //The exam schedule is returned based on days
        public ArrayList whatDays2() {
                return exam_schedule;
        }
}