From 2b0becd31dee628e8e66bd2059948437e200adf9 Mon Sep 17 00:00:00 2001
From: Padinharayil Anoop <panoop@myune.edu.au>
Date: Wed, 2 Aug 2023 15:19:29 +1000
Subject: [PATCH] Fix bugs in DotsAndBoxesGrid
---
.../java/dotsandboxes/DotsAndBoxesGrid.java | 81 +++----------------
1 file changed, 10 insertions(+), 71 deletions(-)
diff --git a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
index a9e7c5b..a4fc40d 100644
--- a/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
+++ b/src/main/java/dotsandboxes/DotsAndBoxesGrid.java
@@ -1,60 +1,26 @@
package dotsandboxes;
-
import java.util.ArrayList;
import java.util.Arrays;
import java.util.function.Consumer;
-/**
- * The state of a dots and boxes grid.
- *
- * A (4, 3) dots and boxes grid looks like this:
- *
- * *-*-*-*
- * | | | |
- * *-*-*-*
- * | | | |
- * *-*-*-*
- *
- * Notice that:
- *
- * - for each row, there is one less horizontal than the number of corner dots
- * - for each row, there are as many verticals as there are corner dots
- * - for each row, there is one less box than the number of corner dots
- * - for each column, there is one less vertical than the number of corner dots.
- * - for each column, there are as many horizontals as there are corner dots.
- * - for each column, there is one less box than the number of corner dots
- *
- * For example, in this (4, 3) grid, there are (3, 3) horizontal lines, and (4, 2) vertical lines, and (3, 2) boxes.
- *
- * We number all lines and boxes by their top-left coordinate.
- *
- * In Java 14+, we might use a Record class for this, but we're using 11+ as an LTS version, so we don't have that yet.
- */
public class DotsAndBoxesGrid {
final int width;
final int height;
- /** The horizontal lines in the grid. True if drawn. */
private boolean[][] horizontals;
-
- /** The vertical lines in the grid. True if drawn. */
private boolean[][] verticals;
-
- /** Which owner (if any) claimed any given box. */
private int[][] boxOwners;
- /** A list of functions to notify when there is an update */
private ArrayList<Consumer<DotsAndBoxesGrid>> watchers = new ArrayList<>();
-
final int players;
private int player = 1;
+
public int getPlayer() {
return player;
}
- /** Moves to the next player */
private void nextPlayer() {
player++;
if (player > players) {
@@ -78,44 +44,30 @@ public class DotsAndBoxesGrid {
}
}
- /** Listens to this grid for changes */
public void addConsumer(Consumer<DotsAndBoxesGrid> consumer) {
watchers.add(consumer);
}
- /** Returns whether a horizontal line has been drawn */
public boolean getHorizontal(int x, int y) {
return horizontals[x][y];
}
- /** Returns whether a vertical line has been drawn */
public boolean getVertical(int x, int y) {
return verticals[x][y];
}
- /** Returns which player owns a box. By convention, 0 is unowned. */
public int getBoxOwner(int x, int y) {
return boxOwners[x][y];
}
-
- /**
- * Checks whether a box has been fully drawn (all four sides)
- * @param x coordinate of the left side of the box
- * @param y coordinate of the top of the box
- * @return true if all four sides have been drawn.
- */
public boolean boxComplete(int x, int y) {
if (x >= width - 1 || x < 0 || y >= height - 1 || y < 0) {
return false;
}
- // A box is complete if the north and south horizontals and the east and west verticals have all been drawn.
- // FIXME: You'll need to fix this code (after writing a test first).
- return true;
+ return horizontals[x][y] && horizontals[x][y+1] && verticals[x][y] && verticals[x+1][y];
}
- /** Tries to claim a box for a player. If the box is complete, sets the ownership and returns true. */
private boolean claimBox(int x, int y, int p) {
if (boxComplete(x, y)) {
boxOwners[x][y] = player;
@@ -125,12 +77,6 @@ public class DotsAndBoxesGrid {
}
}
- /**
- * "Draws" a horizontal line, from grid point (x, y) to (x + 1, y). (i.e. sets that line to true)
- * @param x
- * @param y
- * @return true if it completes a box
- */
public boolean drawHorizontal(int x, int y, int player) {
if (x >= width - 1 || x < 0) {
throw new IndexOutOfBoundsException(String.format("x was %d, which is out of range. Range is 0 to %d", x, width - 1));
@@ -139,11 +85,12 @@ public class DotsAndBoxesGrid {
throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height));
}
- // FIXME: You need to throw an exception if the line was already drawn.
+ if (horizontals[x][y]) {
+ throw new IllegalStateException("This line has already been drawn.");
+ }
this.horizontals[x][y] = true;
- // Try to claim the north or south boxes
boolean claimN = claimBox(x, y-1, player);
boolean claimS = claimBox(x, y, player);
if (claimN || claimS) {
@@ -156,12 +103,6 @@ public class DotsAndBoxesGrid {
}
}
- /**
- * "Draws" a vertical line, from grid point (x, y) to (x, y + 1). (i.e. sets that line to true)
- * @param x
- * @param y
- * @return true if it completes a box
- */
public boolean drawVertical(int x, int y, int player) {
if (x >= width || x < 0) {
throw new IndexOutOfBoundsException(String.format("x was %d, which is out of range. Range is 0 to %d", x, width));
@@ -170,10 +111,12 @@ public class DotsAndBoxesGrid {
throw new IndexOutOfBoundsException(String.format("y was %d, which is out of range. Range is 0 to %d", y, height - 1));
}
- // You need to throw an exception if the line was already drawn.
+ if (verticals[x][y]) {
+ throw new IllegalStateException("This line has already been drawn.");
+ }
this.verticals[x][y] = true;
- // Try to claim the north or south boxes
+
boolean claimE = claimBox(x, y, player);
boolean claimW = claimBox(x-1, y, player);
if (claimE || claimW) {
@@ -184,14 +127,10 @@ public class DotsAndBoxesGrid {
notifyObservers();
return false;
}
-
}
public boolean gameComplete() {
- // Students who took COSC250 might recognise this style of code. This is Java's version of higher order functions.
- // The grid is complete if "for all rows, all the boxes in that row have a non-zero owner"
return Arrays.stream(boxOwners).allMatch((row) -> Arrays.stream(row).allMatch((owner) -> owner > 0));
}
-
-
}
+
--
GitLab