Solution_Assignment 12_Alex

package itu.ip.assignment12;

import java.util.ArrayList;
import java.util.Scanner;


public class Main {
    ArrayList<Teacher> teachers;
    ArrayList<Course> courses;

    /**
     * Constructor for class Course.
     * @param name --name of the course
     * @param teacher --teacher of the course
     */
    public Main(){
        teachers = new ArrayList<Teacher>();
        courses = new ArrayList<Course>();
    }
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        //enterStudentData();
        //printTeacherData();
        //printCourseData();

        //Create objects to test findTeacherWithXCourses()
        Teacher t1 = new Teacher("Mogens", "cpr1", "street1");
        Teacher t2 = new Teacher("Hans", "cpr2", "street2");
        Teacher t3 = new Teacher("Peter", "cpr3", "street3");
        Course c1 = new Course("Intro Programming", t1);
        Course c2 = new Course("Database Design", t1);
        Course c3 = new Course("Algorithm Design", t2);
        Course c4 = new Course("Artificial Intelligence", t2);
        Course c5 = new Course("Model Driven Development",t3);
        Course c6 = new Course("Interactive Multimedia",t3);
        Course c7 = new Course("Interaction Design",t3);

        //Add teachers and courses to Main class
        Main main = new Main();
        main.addTeacher(t1);
        main.addTeacher(t2);
        main.addTeacher(t3);
        main.addCourse(c1);
        main.addCourse(c2);
        main.addCourse(c3);
        main.addCourse(c4);
        main.addCourse(c5);
        main.addCourse(c6);
        main.addCourse(c7);

        //Now test findTeacherWithXCourses method
        main.findTeacherWithXCourses(2);
        main.findTeacherWithXCourses(3);
    }

    private void findTeacherWithXCourses(int numberOfCourses){
        System.out.println("These teachers, if any, has got "+numberOfCourses+" courses");
        for(Teacher teacher : teachers){
            if(teacher.getCourses().size()==numberOfCourses){
                System.out.println(teacher.toString());
            }
        }
    }

    private static void enterStudentData(){
        ArrayList<Student> students = new ArrayList<Student>();
        //add a couple of Studen objects
        students.add(new Student("Hans", "cpr 1"));
        students.add(new Student("Grete", "cpr 2"));

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter 'student name cpr' to create a student'" );
        System.out.println("Enter 'exit' to stop creating student objects" );

        String input = sc.nextLine();
        while(!input.equalsIgnoreCase("exit")){
            //the input requries the word "student" followed by a name and a cpr number
            if(input.toLowerCase().startsWith("student")){
                String[] studentArray = input.split(" ");
                students.add(new Student(studentArray[1],studentArray[2]));
            }
            input = sc.nextLine();
        }

        //print student objects
        for(Student student: students){
            System.out.println(student.toString());
        }
    }

    private static void printTeacherData(){
        ArrayList<Teacher> teachers = new ArrayList<Teacher>();
        Teacher t1 = new Teacher("Mogens", "cpr1", "street1");
        t1.addCourse(new Course(t1));
        teachers.add(t1);
        teachers.add(new Teacher("Sally", "cpr2", "street2"));

        //print teacher information
        for(Teacher teacher : teachers){
            System.out.println(teacher.toString());
        }
    }

    private static void printCourseData(){
        ArrayList<Course> courses = new ArrayList<Course>();
        Teacher t1 = new Teacher("Mogens", "cpr1", "street1");
        Course course1 = new Course(t1);
        courses.add(course1);
        Course course2 = new Course("Intro Programming", 15.0d, t1);

        //print course information
        for(Course course : courses){
            System.out.println(course.toString());
        }
    }

    public void addTeacher(Teacher teacher){
        teachers.add(teacher);
    }

    public void addCourse(Course course){
        courses.add(course);
    }
}
-------------------------------
Student

package itu.ip.assignment12;

import java.util.ArrayList;

public class Student {
    private String name;
    private String cpr;
    ArrayList<Course> courses;
    private static String about = "CourseManager v.1.0, copyright 2012";
    private static String creditBox = "This is the credit box";

    /**
     * Constructor for class Student.
     * @param name --name of student
     * @param cpr --cpr of student
     */
    public Student(String name, String cpr){
        this.name = name;
        this.cpr = cpr;
        System.out.println("A new student '"+name+"' has been created");
    }

    @Override
    /**
     * Returns a string with the fields of the class.
     */
    public String toString(){
        String studentInfo = "";
        studentInfo += "Name: "+name+"\n cpr: "+cpr+"\n";
        studentInfo += "Courses: \n";
        if(courses!=null&&courses.size()>0){
            for(Course course: courses){
            studentInfo += course.getName()+", ";
            }
        }
        return studentInfo;
    }

    /**
     * Adds a course to the student
     */
    public void addCourse(Course course){
        courses.add(course);
    }

    private static void printCredit(){
        System.out.println(creditBox);
    }

    private static void printAbout(){
        System.out.println(about);
    }

    //Getter and setter methods
    public void setName(String name){
        this.name = name;
    }

    public void setCpr(String cpr){
        this.name = cpr;
    }

    public String getName(){
        return name;
    }

    public String getCpr(){
        return cpr;
    }
}

---------------------------------
Teacher

package itu.ip.assignment12;

import java.util.ArrayList;

public class Teacher {
    private String name;
    private String cpr;
    private String address;
    ArrayList<Course> courses;

    /**
     * Constructor for class Teacher.
     * @param name --name of teacher
     * @param cpr --cpr of teacher
     */
    public Teacher(String name, String cpr, String address){
        this.name = name;
        this.cpr = cpr;
        this.address = address;
        courses = new ArrayList<Course>();
        System.out.println("A new teacher '"+name+"' has been created");
    }

    @Override
    /**
     * Returns a string with the fields of the class.
     */
    public String toString(){
        String teacherInfo = "";
        teacherInfo += "Name: "+name+"\n cpr: "+cpr+" address: "+address+"\n";
        teacherInfo += "Courses: \n";
        if(courses!=null&&courses.size()>0){
            for(Course course: courses){
            teacherInfo += course.getName()+", ";
            }
        }
        return teacherInfo;
    }

    /**
     * Adds a course to the teacher
     */
    public void addCourse(Course course){
        courses.add(course);
    }

    public String getName(){
        return name;
    }

    public ArrayList<Course> getCourses(){
        return courses;
    }
}
-----------------------------
Course

package itu.ip.assignment12;

import java.util.ArrayList;

public class Course {
    private String name;
    private Double credits;
    private String examForm;
    private int hoursPrWeek;
    private String courseManager;
    private ArrayList<Teacher> teacherAssistants;
    private Teacher teacher;

    /**
     * Constructor for class Course.
     * @param teacher --teacher of the course
     */
    public Course(Teacher teacher){
        this.teacher = teacher;
        //add course to teacher
        teacher.addCourse(this);
    }

    /**
     * Constructor for class Course.
     * @param name --name of the course
     * @param teacher --teacher of the course
     */
    public Course(String name, Teacher teacher){
        this.name = name;
        this.teacher = teacher;
        //add course to teacher
        teacher.addCourse(this);
    }

    /**
     * Constructor for class Course.
     * @param name --name of the course
     * @param credits --credits of the course
     * @param teacher --teacher of the course
     */
    public Course(String name, Double credits, Teacher teacher){
        this.name = name;
        this.credits = credits;
        this.teacher = teacher;
        //add course to teacher
        teacher.addCourse(this);
    }

    @Override
    /**
     * Returns a string with the fields of the class.
     */
    public String toString(){
        String studentInfo = "";
        studentInfo += "Name: "+name+"\n teacher: "+teacher.getName()+" credits: "+credits+"\n";
        return studentInfo;
    }

    public void setName(String name){
        this.name = name;
    }

    public void setCredits(Double credits){
        this.credits = credits;
    }

    public void setExamForm(String examForm){
        this.examForm = examForm;
    }

    public void setHoursPrWeek(int hoursPrWeek){
        this.hoursPrWeek = hoursPrWeek;
    }

    public void setCourseManager(String courseManager){
        this.courseManager = courseManager;
    }

    public void setTeacher(Teacher teacher){
        this.teacher = teacher;
    }

    public String getName(){
        return name;
    }

    public Double getCredits(){
        return credits;
    }

    public String getExamForm(){
        return examForm;
    }

    public int getHoursPrWeek(){
        return hoursPrWeek;
    }

    public String getCourseManager(){
        return courseManager;
    }

    public Teacher getTeacher(){
        return teacher;
    }
}

----------------------------------------------
MyMatrix

package itu.ip.assignment12;


public class MyMatrix {
    int[][] matrix;

    public static void main(String[] args){
        //Test diagonal method
        MyMatrix m1 = new MyMatrix(2,2,0);
        m1.setValue(0, 0, 1);
        MyMatrix m2 = new MyMatrix(2,2,8);
        //System.out.println(m1.isDiagonal());
        //System.out.println(m2.isDiagonal());

        //Test sum and multiplication methods
        MyMatrix m3 = new MyMatrix(3,3,3);
        MyMatrix m4 = new MyMatrix(3,3,2);

        MyMatrix.sum(m3, m4);
        MyMatrix.multiplication(m3, m4);
        MyMatrix.scalarMultiplication(m4, 2);
    }

    /**
     * Constructor for class MyMatrix.
     * @param dim --number of rows and columns in MyMatrix
     */
    public MyMatrix(int dim){
        matrix = new int[dim][dim];
    }

    /**
     * Constructor for class MyMatrix.
     * @param rows --number of rows in MyMatrix
     * @param cols --number of columns in MyMatrix
     */
    public MyMatrix(int rows, int cols){
        matrix = new int[rows][cols];
    }

    /**
     * Constructor for class MyMatrix.
     * @param rows --number of rows in MyMatrix
     * @param cols --number of columns in MyMatrix
     * @param init --initial number of all numbers
     */
    public MyMatrix(int rows, int cols, int init){
        matrix = new int[rows][cols];
        for(int i = 0; i<matrix.length;i++){
            for(int j = 0; j<matrix[0].length;j++){
                matrix[i][j] = init;
            }
        }
    }

    public void printRowByRow(){
        //the matrix consists of many integer arrays, int[]. These are looped through
        for(int[] row : matrix){
            //every rows consists of many integers. These are looped trough
            for(int i : row){
                System.out.print(i+" ");
            }
            System.out.println("");
        }
    }
    /**
     *  This method checks if the matrix is diagonal
     */
    public boolean isDiagonal(){
        boolean nonZeroValueAlongDiagonal = false;
        //The matrix must be squared
        if(matrix.length!=matrix[0].length){
            return false;
        }
        for(int i = 0; i<matrix.length;i++){
            for(int j = 0; j<matrix[0].length;j++){
                //If an element outside the diagonal is not 0, the matrix is not diagonal.
                //An element is outside the diagonal, if i doesn't equal j.
                if(j!=i&&matrix[i][j]!=0){
                    return false;
                }
                //There has to be at least one non-zero element along the diagonal
                if(j==i&&matrix[i][j]!=0){
                    nonZeroValueAlongDiagonal = true;
                }
            }
        }
        return nonZeroValueAlongDiagonal;
    }

    public static void sum(MyMatrix m1, MyMatrix m2){
        //check if the matrices have the same dimensions
        if(m1.getNumberOfRows()==m2.getNumberOfRows()&&
                m1.getNumberOfCols()==m2.getNumberOfCols()){
            for(int i = 0; i<m1.getNumberOfRows();i++){
                for(int j = 0; j<m1.getNumberOfCols();j++){
                    System.out.print(m1.getValue(i, j)+m2.getValue(i, j) +" ");
                }
                System.out.println("");
            }
        }
    }

    public static void multiplication(MyMatrix m1, MyMatrix m2){
        /*
         * check if the number of columns in the first matrix equals
         * the number of rows in the second matrix
        */
        if(m1.getNumberOfRows()==m2.getNumberOfCols()){
            //create new matrix for the matrix product
            MyMatrix productMatrix = new MyMatrix(m1.getNumberOfCols(), m2.getNumberOfRows(),0);
            for(int i = 0; i<productMatrix.getNumberOfRows();i++){
                for(int j = 0; j<productMatrix.getNumberOfCols();j++){
                    int temp = 0;
                    for(int k = 0;k<m2.getNumberOfCols();k++){
                        temp += m1.getValue(k, j)*m2.getValue(i, k);
                    }
                    System.out.print(temp+" ");
                }
                System.out.println("");
            }
        }
    }

    public static void scalarMultiplication(MyMatrix m1, int scalar){
        //multiply every value in the matrix with the scalarvalue
        for(int i = 0; i<m1.getNumberOfRows();i++){
            for(int j = 0; j<m1.getNumberOfCols();j++){
                System.out.print(m1.getValue(i, j)*scalar +" ");
            }
            System.out.println("");
        }
    }

    public void setValue(int rowPos, int colPos, int newValue){
        matrix[rowPos][colPos] = newValue;
    }

    public void setMatrix(int[][] matrix){
        this.matrix = matrix;
    }

    public int[][] getMatrix(){
        return matrix;
    }

    public int getValue(int rowPos, int colPos){
        return matrix[rowPos][colPos];
    }

    public int[] getDimensions(){
        int[] returnArray = new int[2];
        returnArray[0] = matrix.length;
        returnArray[1] = matrix[0].length;
        return returnArray;
    }

    public int getNumberOfRows(){
        return matrix.length;
    }

    public int getNumberOfCols(){
        return matrix[0].length;
    }
}