java语言程序设计第十版课后答案

import javafx.animation.KeyFrame; import javafx.animation.Timeline; import javafx.application.Application; import javafx.geometry.Pos; import javafx.scene.Scene; import javafx.scene.control.Button; import javafx.scene.control.Label; import javafx.scene.layout.BorderPane; import javafx.scene.layout.GridPane; import javafx.scene.paint.Color; import javafx.scene.shape.Circle; import javafx.stage.Stage; import javafx.util.Duration; public class Exercise16_15Extra extends Application { private Cell[][] cells = new Cell[6][7]; private Timeline flashAnimation = new Timeline( new KeyFrame(Duration.millis(400), e -> { setFourCellColor(); })); private Label lblStatus = new Label(); @Override // Override the start method in the Application class public void start(Stage primaryStage) { flashAnimation.setCycleCount(Timeline.INDEFINITE); GridPane gridPane = new GridPane(); gridPane.setAlignment(Pos.CENTER); gridPane.setHgap(5); gridPane.setVgap(5); gridPane.setStyle("-fx-background-color: green"); for (int i = 0; i < 6; i++) { for (int j = 0; j < 7; j++) { cells[i][j] = new Cell(i, j); gridPane.add(cells[i][j], j, i); } } BorderPane pane = new BorderPane(); pane.setBottom(lblStatus); BorderPane.setAlignment(lblStatus, Pos.CENTER); pane.setCenter(gridPane); // Create a scene and place it in the stage Scene scene = new Scene(pane, 200, 200); primaryStage.setTitle("Exercise16_15"); // Set the stage title primaryStage.setScene(scene); // Place the scene in the stage primaryStage.show(); // Display the stage } private void startOver() { nextDisc = 'R'; result = null; for (int i = 0; i < cells.length; i++) { for (int j = 0; j < cells[i].length; j++) { cells[i][j].token = ' '; } } } private char nextDisc = 'R'; private int[][] result; private Button btStartOver = new Button("Start Over"); class Cell extends Circle { char token = ' '; int i, j; boolean isFlashing; private boolean available() { return (token == ' ' && (i == 5 || cells[i + 1][j].token != ' ')); } public Cell(int i, int j) { super(10, 10, 20); this.setFill(Color.WHITE); this.setStroke(Color.BLACK); this.i = i; this.j = j; this.setOnMousePressed(e -> { if (result != null) { return; // Game is over } if (available()) { token = nextDisc; if (token == 'Y') { this.setFill(Color.YELLOW); } else if (token == 'R') { this.setFill(Color.RED); } result = isConsecutiveFour(cells); if (result != null) { flashAnimation.play(); } else if (nextDisc == 'R') { nextDisc = 'Y'; } else { nextDisc = 'R'; } // Check if there is a draw? if (isDraw()) { lblStatus.setText("A draw, no winner, start over"); startOver(); } } }); } } private boolean isDraw() { for (int i = 0; i < cells.length; i++) { for (int j = 0; j < cells[i].length; j++) { if (cells[i][j].token == ' ') { return false; } } } return true; } public static int[][] isConsecutiveFour(Cell[][] cells) { char[][] values = new char[cells.length][cells[0].length]; for (int i = 0; i < cells.length; i++) { for (int j = 0; j < cells[i].length; j++) { values[i][j] = cells[i][j].token; } } return isConsecutiveFour(values); } /** * Return null if no consecutive four; otherwise, return the locations of the * four consecutive cells. The locations are in (result[0][0], result[0][1]), * (result[1][0], result[1][1]), (result[2][0], result[2][1]), and * (result[3][0], result[3][1]) */ public static int[][] isConsecutiveFour(char[][] values) { int numberOfRows = values.length; int numberOfColumns = values[0].length; // Check rows for (int i = 0; i < numberOfRows; i++) { if (isConsecutiveFour(values[i]) != null) { int[][] result = new int[4][2]; result[0][0] = result[1][0] = result[2][0] = result[3][0] = i; int k = isConsecutiveFour(values[i]); result[0][1] = k; result[1][1] = k + 1; result[2][1] = k + 2; result[3][1] = k + 3; return result; } } // Check columns for (int j = 0; j < numberOfColumns; j++) { char[] column = new char[numberOfRows]; // Get a column into an array for (int i = 0; i < numberOfRows; i++) { column[i] = values[i][j]; } if (isConsecutiveFour(column) != null) { int[][] result = new int[4][2]; result[0][1] = result[1][1] = result[2][1] = result[3][1] = j; int k = isConsecutiveFour(column); result[0][0] = k; result[1][0] = k + 1; result[2][0] = k + 2; result[3][0] = k + 3; return result; } } // Check major diagonal (lower part) for (int i = 0; i < numberOfRows - 3; i++) { int numberOfElementsInDiagonal = Math.min(numberOfRows - i, numberOfColumns); char[] diagonal = new char[numberOfElementsInDiagonal]; for (int k = 0; k < numberOfElementsInDiagonal; k++) { diagonal[k] = values[k + i][k]; } if (isConsecutiveFour(diagonal) != null) { int[][] result = new int[4][2]; int k = isConsecutiveFour(diagonal); result[0][0] = k + i; result[1][0] = k + 1 + i; result[2][0] = k + 2 + i; result[3][0] = k + 3 + i; result[0][1] = k; result[1][1] = k + 1; result[2][1] = k + 2; result[3][1] = k + 3; return result; } } // Check major diagonal (upper part) for (int j = 1; j < numberOfColumns - 3; j++) { int numberOfElementsInDiagonal = Math.min(numberOfColumns - j, numberOfRows); char[] diagonal = new char[numberOfElementsInDiagonal]; for (int k = 0; k < numberOfElementsInDiagonal; k++) { diagonal[k] = values[k][k + j]; } if (isConsecutiveFour(diagonal) != null) { int[][] result = new int[4][2]; int k = isConsecutiveFour(diagonal); result[0][0] = k; result[1][0] = k + 1; result[2][0] = k + 2; result[3][0] = k + 3; result[0][1] = k + j; result[1][1] = k + 1 + j; result[2][1] = k + 2 + j; result[3][1] = k + 3 + j; return result; } } // Check sub-diagonal (left part) for (int j = 3; j < numberOfColumns; j++) { int numberOfElementsInDiagonal = Math.min(j + 1, numberOfRows); char[] diagonal = new char[numberOfElementsInDiagonal]; for (int k = 0; k < numberOfElementsInDiagonal; k++) { diagonal[k] = values[k][j - k]; } if (isConsecutiveFour(diagonal) != null) { int[][] result = new int[4][2]; int k = isConsecutiveFour(diagonal); result[0][0] = k; result[1][0] = k + 1; result[2][0] = k + 2; result[3][0] = k + 3; result[0][1] = j - k; result[1][1] = j - k - 1; result[2][1] = j - k - 2; result[3][1] = j - k - 3; return result; } } // Check sub-diagonal (right part) for (int i = 1; i < numberOfRows - 3; i++) { int numberOfElementsInDiagonal = Math.min(numberOfRows - i, numberOfColumns); char[] diagonal = new char[numberOfElementsInDiagonal]; for (int k = 0; k < numberOfElementsInDiagonal; k++) { diagonal[k] = values[