refactored win condition methods, added docs

src/main/java/inf101/v20/sem2/mnkgames/MNKGame.java

@@ -86,13 +86,13 @@ public abstract class MNKGame {
 			throw new IllegalArgumentException("Cannot add a piece to this position");
 		if(grid.get(x, y) != Piece.NONE)
 			throw new IllegalArgumentException("Position is already filled");
-		
+
 		grid.set(x, y, currentPlayer);
 
 		if(checkWinCondition(x, y)) {
 			winnerPiece = currentPlayer;
 		}
-		
+
 		currentPlayer = currentPlayer.next(); 
 	}
 
@@ -102,14 +102,14 @@ public abstract class MNKGame {
 	public boolean hasWinner() {
 		return winnerPiece!=Piece.NONE;
 	}
-	
+
 	/**
 	 * @return the piece that won the game
 	 */
 	public Piece getWinner() {
 		return winnerPiece;
 	}
-	
+
 	/**
 	 * Checks for k in a row such that the line intersects (x, y) 
 	 * @param x the x coordinate 
@@ -117,82 +117,138 @@ public abstract class MNKGame {
 	 * @return true if there are k in a row such that the line intersects (x, y), false otherwise
 	 */
 	private boolean checkWinCondition(int x, int y) {
-				int count = 0;
-				Piece current = grid.get(x, y);
-				if(current==Piece.NONE)
-					return false;
-				
-				System.out.println();
-				System.out.println("Currently at " + x + "," + y + " value " + current);
-				System.out.println();
-				
-				//horizontal 
-				for (int i = x-k; i<x+k; i++) {
-					if(i <0 || i>=getWidth())
-						continue;
-					System.out.println("Horizontal Looking at \n" + debugToString(i, y) + ": count is " + count);
-					if(grid.get(i, y) != current) {
-						count = 0;
-					}
-					else {
-						count++;
-					}
-					if(count==k)
-						return true;
-				}
+		Piece current = grid.get(x, y);
+		if(current==Piece.NONE)
+			return false;
+//		System.out.println();
+//		System.out.println("Currently at " + x + "," + y + " value " + current);
+//		System.out.println();
+		if(checkHorizontal(x, y, current))
+			return true;
+		if(checkVertical(x, y, current))
+			return true;
+		if(checkDiagonalTLBR(x, y, current))
+			return true;
+		if(checkDiagonalTRBL(x, y, current))
+			return true;
+		
+		return false;
+	}
+
+	/**
+	 * Checks for k pieces in a row diagonally around from the pivot point (x, y)
+	 * such that for x in X and y in Y this method checks the following positions 
+	 * (x, y)
+	 * (x-1, y+1)
+	 * (x-2, y+3)
+	 * ..
+	 *    
+	 * @param x the x-coordinate 
+	 * @param y the y-coordinate
+	 * @param current the value of the piece at (x,y)
+	 * @return true if a k-row was found, false otherwise
+	 */
+	private boolean checkDiagonalTRBL(int x, int y, Piece current) {
+		int count = 0;
+		for (int i = x+k, j=y-k; i>x-k && j<y+k; i--, j++) {
+			if(i <0 || j <0 || i>=getWidth() || j>=getHeight())
+				continue;
+			System.out.println("Diagonal TR-BL Looking at \n" + debugToString(i, j) + ": count is " + count);
 
+			if(grid.get(i, j) != current) {
 				count = 0;
-				//vertical 
-				for (int j = y-k; j<y+k; j++) {
-					if(j <0 || j>=getHeight())
-						continue;
-					System.out.println("Vertical Looking at \n" + debugToString(x, j) + ": count is " + count);
-					if(grid.get(x, j) != current) {
-						count = 0;
-					}
-					else {
-						count++;
-					}
-					if(count==k)
-						return true;
-				}
+			}
+			else {
+				count++;
+			}
+			if(count==k)
+				return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Checks for k pieces in a row diagonally around from the pivot point (x, y)
+	 * such that for i in X and j in Y this method checks the following positions 
+	 * (x, y)
+	 * (x+1, y+1)
+	 * (x+2, y+3)
+	 * ..
+	 *    
+	 * @param x the x-coordinate 
+	 * @param y the y-coordinate
+	 * @param current the value of the piece at (x,y)
+	 * @return true if a k-row was found, false otherwise
+	 */
+	private boolean checkDiagonalTLBR(int x, int y, Piece current) {
+		int count = 0;
+		for (int i = x-k, j=y-k; i<x+k && j<y+k; i++, j++) {
+			if(i <0 || j <0 || i>=getWidth() || j>=getHeight())
+				continue;
+			System.out.println("Diagonal TL-BR Looking at \n" + debugToString(i, j) + ": count is " + count);
 
+			if(grid.get(i, j) != current) {
 				count = 0;
-				//diagonal (0,0) -> (l, l) where l := min(m, n)
-				for (int i = x-k, j=y-k; i<x+k && j<y+k; i++, j++) {
-					if(i <0 || j <0 || i>=getWidth() || j>=getHeight())
-						continue;
-					System.out.println("Diagonal TL-BR Looking at \n" + debugToString(i, j) + ": count is " + count);
-
-					if(grid.get(i, j) != current) {
-						count = 0;
-					}
-					else {
-						count++;
-					}
-					if(count==k)
-						return true;
-				}
-				
+			}
+			else {
+				count++;
+			}
+			if(count==k)
+				return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Checks for k pieces in a row along the y-axis from the pivot point (x, y) 
+	 * @param x the x-coordinate 
+	 * @param y the y-coordinate
+	 * @param current the value of the piece at (x,y)
+	 * @return true if a k-row was found, false otherwise
+	 */
+	private boolean checkVertical(int x, int y, Piece current) {
+		int count = 0;
+		for (int j = y-k; j<y+k; j++) {
+			if(j <0 || j>=getHeight())
+				continue;
+			System.out.println("Vertical Looking at \n" + debugToString(x, j) + ": count is " + count);
+			if(grid.get(x, j) != current) {
 				count = 0;
-				//diagonal (0,n) -> (m, 0) where l := min(m, n)
-				for (int i = x+k, j=y-k; i>x-k && j<y+k; i--, j++) {
-					if(i <0 || j <0 || i>=getWidth() || j>=getHeight())
-						continue;
-					System.out.println("Diagonal TR-BL Looking at \n" + debugToString(i, j) + ": count is " + count);
-
-					if(grid.get(i, j) != current) {
-						count = 0;
-					}
-					else {
-						count++;
-					}
-					if(count==k)
-						return true;
-				}
+			}
+			else {
+				count++;
+			}
+			if(count==k)
+				return true;
+		}
 		return false;
 	}
-	
+
+	/**
+	 * Checks for k pieces in a row along the x-axis from the pivot point (x, y) 
+	 * @param x the x-coordinate 
+	 * @param y the y-coordinate
+	 * @param current the value of the piece at (x,y)
+	 * @return true if a k-row was found, false otherwise
+	 */
+	private boolean checkHorizontal(int x, int y, Piece current) {
+		int count = 0;
+		for (int i = x-k; i<x+k; i++) {
+			if(i <0 || i>=getWidth())
+				continue;
+			System.out.println("Horizontal Looking at \n" + debugToString(i, y) + ": count is " + count);
+			if(grid.get(i, y) != current) {
+				count = 0;
+			}
+			else {
+				count++;
+			}
+			if(count==k)
+				return true;
+		}
+		return false;
+	}
+
 	@Override
 	public String toString() {
 		String r = "";
@@ -204,7 +260,7 @@ public abstract class MNKGame {
 		}
 		return r;
 	}
-	
+
 	private String debugToString(int x, int y) {
 		System.out.println("x="+x+", y="+y);
 		String r = "";
@@ -220,5 +276,5 @@ public abstract class MNKGame {
 		}
 		return r;
 	}
-	
+
 }