// ============================
// Q1
// ============================
class Wallet {

	private int value;

	public Wallet(int v) {
		value = v;
	}

	public void change(int v) {
		value += v;
	}

	public String tell() {
		return value + " ";
	}
}

class CheatWallet extends Wallet {

	private Wallet secretWallet = new Wallet(0);

	public CheatWallet() {
		super(0);
	}

	public void take10(Wallet w1) {

		w1.change(-15);

		secretWallet.change(5);

		this.change(10);
	}

	public String tell() {

		return super.tell() + " " + secretWallet.tell();
	}
}

public class Main {

	public static void main(String[] args) {

		Wallet w = new Wallet(100);

		CheatWallet cw = new CheatWallet();

		cw.take10(w);

		System.out.println(cw.tell()); // Statement A

		System.out.println(w.tell()); // Statement B
	}
}


// ============================
// Q2
// ============================

    // ============================
    // Main
    // ============================

    public class Main {
        public static void main(String[] args) {
            /* Part A */
            Logbook lb = Logbook.getInstance();
            Student a = new Student("Ada");
            Student b = new Student("Bob");
            Student c = new Student("Candy");
            Student d = new Student("Doris");
            Student e = new Student("Emily");
            Student f = new Student("Frank");
            Student g = new Student("Gabriel");
            c.infect(d); // Candy infects Doris
            d.infect(g); // Doris infects Gabriel
            lb.show_count(); // Output: 2 records
            /* Part B */
            lb.showPathTo(g); // Output: Candy => Doris => Gabriel
            lb.showSources(); // Output: Candy
            a.infect(b);
            b.infect(f);
            a.infect(e);
            lb.showPathTo(f); // Output: Ada => Bob => Frank
            lb.showPathTo(e); // Output: Ada => Emily
            lb.showSources(); // Output: Candy Ada
            lb.show_count(); // Output: 5 records
        }
    }
        
    // ============================
    // Student.java
    // ============================

    public class Student {
        private String name;

        public Student(String name) {
            this.name = name;
        }

        public String getName() {
            return name;
        }

        // Add your own code below
    }

    // ============================
    // Logbook.java
    // ============================

    import java.util.*;

    public class Logbook {
        private ArrayList<InfectionRecord> log;

        // Add your own code below
    }

    // ============================
    // InfectionRecord.java
    // ============================

    import java.util.*;

    public class InfectionRecord {

        // Add your own code below
    }


// ============================
// Q3
// ============================

    // ============================
    // Main
    // ============================

    import java.util.ArrayList;

    public class Main {
        public static void main(String[] args) {
            Student a = new Student("Amy");
            Student b = new Student("Bob");
            Student c = new Student("Cathy");
            Student d = new Student("Daisy");
            StudentGroup x = new StudentGroup();
            StudentGroup y = new StudentGroup();
            b.join(x);
            b.join(y);
            c.join(x);
            c.join(y);
            d.join(y);
            ArrayList<Project> projects = new ArrayList<>();
            projects.add(new Project(x, "Honesty"));
            projects.add(new Project(y, "Sports"));
            projects.add(new Project(y, "Crime"));
            projects.add(new Project(a, "Tourism"));
            projects.add(new Project(b, "Earthquakes"));
            projects.add(new Project(a, "Cookery"));
            for (Project p : projects) {
                p.showdetails();
            }
        }
    }

    // ============================
    // Output
    // ============================
    /*
    [Honesty] by Bob Cathy
    [Sports] by Bob Cathy Daisy
    [Crime] by Bob Cathy Daisy
    [Tourism] by Amy
    [Earthquakes] by Bob
    [Cookery] by Amy
    */


    // ============================
    // Project
    // ============================
    public class Project {
        private String title;
        private Writer writer;

        public Project(Writer writer, String title) {
            this.title = title;
            this.writer = writer;
        }

        public void showdetails() {
            System.out.printf("[%s] by %s\n", title, writer.say_I_am());
        }
    }

    // ============================
    // Writer
    // ============================
    interface Writer {
        String say_I_am();
    }


// ============================
// Q4
// ============================

    // ============================
    // MissingValueEx.java
    // ============================

    public class MissingValueEx extends Exception {
        public MissingValueEx() {
            super("Missing value!");
        }

        public MissingValueEx(String msg) {
            super(msg);
        }
    }

    // ============================
    // OutOfRangeEx.java
    // ============================

    public class OutOfRangeEx extends Exception {
        private int x, v1, v2;

        public OutOfRangeEx(int x, int v1, int v2) {
            this.x = x;
            this.v1 = v1;
            this.v2 = v2;
        }

        @Override
        public String getMessage() {
            return x +
                    " is out of range (" + v1 + ", " + v2 + ")";
        }
    }    

    // ============================
    // Main.java
    // ============================

    import java.util.*;

    public class Main {
        public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);
            System.out.print("d m y: ");
            String input = sc.nextLine(); // Accept a string until \n ('\n' is not stored)
            try {
                Day d = new Day(input);
                System.out.println("Day created: " + d);
            }


            
            sc.close();
        }
    }

    // ============================
    // Day.java
    // ============================

    import java.util.*;

    public class Day {
        private int y, m, d;









        
        @Override
        public String toString() { // given
            return d + "-" + m + "-" + y;
        }
    }