====== homework1 ======
==== TestHW.java ====
<code java>
package homework1;

import org.junit.*;
import static org.junit.Assert.*;

public class TestHW {

    @Test 
    public void test01() {
        Point p1 = new Point(2, 5);
        Point p2 = new Point(5, 2);
        assertEquals("(2,5) is to be equal to (2,5).", p1, new Point(2, 5));
        assertFalse("(2,5) is not to be equal to (5,2).", p1.equals(p2));
        assertFalse("(5,2) is not to be equal to (2,5).", p2.equals(p1));

        Canvas c = new HashCanvas("CC");
        c.put(new Point(2, 5), 1);
        c.put(new Point(5, 2), 2);
        c.put(new Point(8, 2), 5);
        c.put(new Point(1, 3), 9);
        c.put(new Point(1, 4), 2);
        c.put(new Point(2, 8), 5);
        c.put(new Point(3, 5), 3);
        c.put(new Point(2, 2), 2);

        assertEquals("Name of canvas is to be CC.", "CC", c.getName());
        assertTrue("Canvas should contain (2, 8).", c.contains(new Point(2, 8)));
        assertFalse("Canvas should not contain (2, 7).", c.contains(new Point(2, 7)));
        assertEquals("Colour of (3,5) is to be 3.", 3, c.get(new Point(3,5)));
    }
    
    @Test 
    public void test02() {
        MyCanvas c = new MyHashCanvas("BB", 10);
        c.put(new Point(2, 5), 1);
        c.put(new Point(5, 2), 2);
        c.put(new Point(8, 2), 5);
        c.put(new Point(1, 3), 9);
        c.put(new Point(1, 4), 2);
        c.put(new Point(2, 8), 5);
        c.put(new Point(3, 5), 3);
        c.put(new Point(2, 2), 2);

        assertEquals("Name of canvas is to be BB.", "BB", c.getName());
        assertEquals("Number of colour 2 is to be 3.", 3, c.numOfColour(2));
        c.remove(new Point(1, 4));
        assertEquals("Number of colour 2 is to be 2.", 2, c.numOfColour(2));
    }

}
</code>
===== solution =====
==== MyHashCanvas.java ====
<code java>
package homework1.solution;

public class MyHashCanvas extends ija.HashCanvas implements ija.MyCanvas {
        int pole[];

        public MyHashCanvas(String ObjectName, int MaxPocetBarev) {
                super(ObjectName);
                this.pole = new int[MaxPocetBarev];
        }

        public void put(Object o1, int o2) {
                super.put(o1, o2);
                pole[o2]++;
        }

        public void remove(Object o) {
                pole[super.get(o)]--;
                super.remove(o);
        }

        public int numOfColour(int c) {
                return pole[c];
        }
}
</code>

==== Point.java ====
<code java>
package homework1.solution;

public class Point {
        int x;
        int y;

        public Point(int x, int y) {
                this.x = x;
                this.y = y;
        }

        public boolean equals(Object o) {
                if (o instanceof Point) {
                        Point p = (Point)o;
                        if (x == p.x && y == p.y) {
                                return true;
                        }
                }
                return false;
        }

        public int hashCode() {
                return this.x * this.y + this.x;
        }
}
</code>