数据结构与算法分析第一章Java类(04)

定义一个名为GenericCoin的类表示一枚没有面值也没有名字的硬币。这枚硬币应该有一个顶面与一个底面&＃xff0c;并且可以标明哪一面朝上。应该能够抛掷这枚硬币使之随机掉落&＃xff0c;或者顶面朝上&＃xff0c;或者底面朝上。

a.编写一个程序将两枚硬币各抛掷50次。记录并报告每枚硬币各有多少次顶面朝上&＃xff0c;报告那一枚硬币顶面朝上的次数多

b.编写一个程序来玩一个简单的抛硬币游戏。要求用户猜测隐蔽会是顶面还是底面朝上&＃xff0c;然后跑硬币&＃xff0c;并将结果告诉用户&＃xff0c;宣告用户的猜测是否正确&＃xff0c;并将结果裂成表格。用户可以持续的玩这个游戏&＃xff0c;想玩多久就玩多久。当用户退出时&＃xff0c;显示一个游戏总结&＃xff0c;包括&＃xff1a;抛硬币的次数&＃xff0c;顶面朝上的次数&＃xff0c;底面朝上的次数&＃xff0c;猜测正确的次数&＃xff0c;和猜测正确的百分比。并可以应用户要求以图形演示每次抛硬币的结果。

GenericCoin类&＃xff0c;非常简单&＃xff0c;里面有个方法cast表示抛一次硬币动作&＃xff0c;用了java里的随机数和取绝对值操作(防止出现负数)&＃xff0c;这里用了枚举类表示硬币的正面和反面

package com.crazycoder2010.datastructure.ch01;import java.util.Random;public class GenericCoin {//表示硬币的正面和反面public static enum FACE{FONT,BACK;}private FACE face;public FACE getFace() {return face;}public void cast(){int index &＃61; 1;Random random &＃61; new Random();index &＃61; random.nextInt()%2;this.face &＃61; FACE.values()[Math.abs(index)];}
}测试称许a-模拟两个硬币一起抛做数据对比

package com.crazycoder2010.datastructure.ch01;import com.crazycoder2010.datastructure.ch01.GenericCoin.FACE;public class GenericCoinTest {public static void main(String[] args) {GenericCoin coin1 &＃61; new GenericCoin();int index1 &＃61; countFace(coin1,50);GenericCoin coin2 &＃61; new GenericCoin();int index2 &＃61; countFace(coin2,50);System.out.println("Coin 1:"&＃43;index1);System.out.println("Coin 2:"&＃43;index2);}private static int countFace(GenericCoin coin,int times){int total &＃61; 0;for(int i &＃61; 0;i }
这个称许的输出结果为&＃xff1a;

Coin 1:23
Coin 2:21

测试程序b-提供ui界面给用户&＃xff0c;这里用的是jframe

package com.crazycoder2010.datastructure.ch01;import java.awt.FlowLayout;
import java.awt.HeadlessException;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;import com.crazycoder2010.datastructure.ch01.GenericCoin.FACE;public class GenericCoinTestUI extends JFrame {private static int index &＃61; 0;private List results &＃61; new ArrayList();// 保存所有猜测结果private Map actual &＃61; new HashMap();//实际硬币展示的数量,key:正面/反面&＃xff0c;value:对应的硬币正面或反面出现的次数private static final long serialVersionUID &＃61; 2948063316297165651L;public GenericCoinTestUI() throws HeadlessException {super();setTitle("抛硬币游戏");setSize(500, 550);setResizable(false);this.getContentPane().setLayout(new FlowLayout());//游戏开始之前反面/正面出现的实际次数都为0actual.put(FACE.FONT, 0);actual.put(FACE.BACK, 0);this.addWindowListener(new WindowAdapter() {&＃64;Overridepublic void windowClosing(WindowEvent e) {StringBuffer message &＃61; new StringBuffer("----游戏总结----\n");message.append("猜测总次数&＃xff1a;").append(results.size()).append("\n");message.append("正面次数&＃xff1a;").append(actual.get(FACE.FONT)).append("\n");message.append("反面次数&＃xff1a;").append(actual.get(FACE.BACK)).append("\n");int success &＃61; doSummarySuccess(results);message.append("猜中次数&＃xff1a;").append(success).append("\n");message.append("猜中百分比&＃xff1a;").append(Float.valueOf(success)*100/results.size()).append("%\n");JOptionPane.showMessageDialog(null, message);System.exit(0);}});final AbstractTableModel tableModel &＃61; new MyTable(this.results);JTable table &＃61; new JTable(tableModel);JScrollPane scrollPane &＃61; new JScrollPane(table);final JComboBox faces &＃61; new JComboBox();faces.addItem("正面");faces.addItem("反面");this.getContentPane().add(faces);JButton throwButton &＃61; new JButton("猜猜");this.getContentPane().add(throwButton);final JLabel label &＃61; new JLabel();this.getContentPane().add(label);throwButton.addActionListener(new ActionListener() {&＃64;Overridepublic void actionPerformed(ActionEvent e) {GenericCoin coin &＃61; new GenericCoin();coin.cast();actual.put(coin.getFace(), actual.get(coin.getFace())&＃43;1);Guess guess &＃61; new Guess(&＃43;&＃43;index, FACE.values()[faces.getSelectedIndex()],coin.getFace() &＃61;&＃61; FACE.values()[faces.getSelectedIndex()]);results.add(guess);label.setText(guess.isRight()?"猜中了&＃xff01;":"没猜中&＃xff01;");tableModel.fireTableDataChanged();}});this.getContentPane().add(scrollPane);}public static void main(String[] args) {new GenericCoinTestUI().setVisible(true);}private int doSummarySuccess(List guesses){int total &＃61; 0;for(Guess guess : guesses){if(guess.isRight()){total&＃43;&＃43;;}}return total;}private static class MyTable extends AbstractTableModel {private String[] header &＃61; { "索引", "猜测", "猜中" };private List guesses;private MyTable(List guesses){this.guesses &＃61; guesses;}&＃64;Overridepublic int getRowCount() {return guesses.size();}&＃64;Overridepublic String getColumnName(int column) {return header[column];}&＃64;Overridepublic int getColumnCount() {return header.length;}&＃64;Overridepublic Object getValueAt(int rowIndex, int columnIndex) {Guess guess &＃61; guesses.get(rowIndex);if(columnIndex &＃61;&＃61; 0){return guess.getIndex();}else if(columnIndex &＃61;&＃61; 1){return guess.getFace();}else if(columnIndex &＃61;&＃61; 2){return guess.isRight();}return null;}}private static class Guess {//这个类表示用户的一次猜测行为private int index;//猜测的索引&＃xff0c;第一次猜猜&＃xff0c;第二次猜测。。。private FACE face;//用户猜测的硬币面-正面或反面private boolean right;//这次猜测活动用户是否猜中public Guess(int index, FACE face, boolean right) {this.index &＃61; index;this.face &＃61; face;this.right &＃61; right;}public int getIndex() {return index;}public FACE getFace() {return face;}public boolean isRight() {return right;}}
}
看一下运行结果界面&＃xff1a;