You are to implement five classes. The behavior of each class is described below.

Question

You are to implement five classes. The behavior of each class is described below.

Class getChar getMove

Bird B Randomly selects one of the four directions each time

Frog F Picks a random direction, moves 3 in that direction, repeat (same as bird, but staying in a single direction longer)

Mouse M West 1, north 1, repeat (zig zag to the NW)

Turtle T South 5, west 5, north 5, east 5, repeat (clockwise box)

Wolf W Make a W shape

For the random moves, each possible choice must be equally likely. You may use either a Random object or the Math.random() method to obtain pseudorandom values.

The first four of these classes won’t use the CritterInfo object that is passed to getMove. This object is provided in case you want to do something with this information in defining your Wolf class. See the description of CritterInfo later in the writeup.

The critter world is divided into cells that have integer coordinates, much like the pixels in a DrawingPanel. There are 100 cells across and 50 cells up and down. As with the DrawingPanel, the upper-left cell has coordinates (0, 0), increasing x values move you right and increasing y values move you down.

Notice that the Critter class defines five constants for the various directions. You can refer to these using the name of the interface (Critter.NORTH, Critter.SOUTH, etc) or you can refer to them directly (NORTH, SOUTH, etc) because you are implementing the interface. Your code should not depend upon the specific values assigned to these constants, although you may assume they will always be of type int. You will lose style points if you fail to use the named constants when appropriate. As noted above, your critter can stay in its current location by indicating that the direction it wants to move is CENTER.

Answer 1

Here is the implementation of the five classes:

```java
import java.util.Random;

public class Bird implements Critter {
private Random random;

public Bird() {
random = new Random();
}

public char getChar() {
return 'B';
}

public int getMove(CritterInfo info) {
int direction = random.nextInt(4);
return direction;
}
}

public class Frog implements Critter {
private Random random;
private int direction;
private int steps;

public Frog() {
random = new Random();
direction = random.nextInt(4);
steps = 0;
}

public char getChar() {
return 'F';
}

public int getMove(CritterInfo info) {
if (steps < 3) {
steps++;
} else {
direction = random.nextInt(4);
steps = 1;
}
return direction;
}
}

public class Mouse implements Critter {
private int x;
private int y;

public Mouse() {
x = 0;
y = 0;
}

public char getChar() {
return 'M';
}

public int getMove(CritterInfo info) {
int direction;
if (x % 2 == 0) {
if (y < 49) {
direction = Critter.NORTH;
y++;
} else {
direction = Critter.WEST;
x++;
}
} else {
if (y > 0) {
direction = Critter.NORTH;
y--;
} else {
direction = Critter.WEST;
x++;
}
}
return direction;
}
}

public class Turtle implements Critter {
private int step;
private int direction;

public Turtle() {
step = 0;
direction = Critter.SOUTH;
}

public char getChar() {
return 'T';
}

public int getMove(CritterInfo info) {
int[] directions = {Critter.SOUTH, Critter.WEST, Critter.NORTH, Critter.EAST};
if (step < 5) {
direction = directions[step];
step++;
} else {
step = 1;
}
return direction;
}
}

public class Wolf implements Critter {
public char getChar() {
return 'W';
}

public int getMove(CritterInfo info) {
int row = info.getRow();
int col = info.getCol();

if (row == col || col == 99 - row) {
return Critter.NORTH;
} else if ((row >= 1 && row <= 3) && (col >= 1 && col <= 7)) {
return Critter.EAST;
} else if (col >= 2 && col <= 6) {
return Critter.WEST;
} else {
return Critter.SOUTH;
}
}
}
```

Note: The implementation of the `Wolf` class uses the `CritterInfo` object passed to `getMove` to determine its move. The `getRow` and `getCol` methods of `CritterInfo` return the row and column of the cell that the `Wolf` currently occupies.