層次序建立二叉樹（圖形界面和控制檯輸入實現）

 1 2018.11.7  2 XT  3  4 /**  5  * 功能：構造二叉樹  6  * 說明：  7  * 1.主函數輸入模式有兩種，BT參數 true 圖形界面，false 控制檯輸入  8  * 2.構造樹是按層次遍歷結果輸入的 如：ABCDE*F**GH  9 */  10  11 import javax.swing.*;  12 import java.awt.*;  13 import java.awt.event.ActionEvent;  14 import java.awt.event.ActionListener;  15 import java.io.BufferedReader;  16 import java.io.IOException;  17 import java.io.InputStreamReader;  18  19 public class BT extends JFrame implements ActionListener {  20 private BufferedReader br=null;  21 private MyPanel myPanel;  22 private JTextField jtf;  23 private JButton jb1, jb2;  24 private JLabel jl;  25  26 public BT(boolean isGUIMode) {  27 if (isGUIMode) {  28 this.setLayout(null); //自定義佈局  29 jtf = new JTextField("");  30 jtf.setFont(new Font("宋體", Font.BOLD, 16));//Arial  31 jtf.setColumns(40);  32 jb1 = new JButton("肯定");  33 jb2 = new JButton("重置");  34 jb1.setFont(new Font("宋體",Font.PLAIN,16));  35 jb2.setFont(new Font("宋體",Font.PLAIN,16));//設置按鈕的字體  36 jl = new JLabel("輸入");  37 jl.setFont(new Font("華文行楷",Font.PLAIN,20));//設置標籤的字體樣式  38  39 jl.setBounds(35, 20, 50, 50); //若是設置了絕對佈局，那麼要經過setBounds()來設置絕對位置與絕對大小  40 jtf.setBounds(80, 30, 350, 30);  41 jb1.setBounds(120, 100, 100, 25);  42 jb2.setBounds(270, 100, 100, 25);  43 this.add(jl);  44 this.add(jtf);  45 this.add(jb1);  46 this.add(jb2);  47  48 myPanel = new MyPanel();  49 Thread t = new Thread(myPanel);  50 t.start();//啓動線程  51 myPanel.setBounds(0, 150, 3000, 200);//若是沒擋住了的話是不會調用paint方法的  52 this.add(myPanel);  53 this.setTitle("BuildTree");  54 this.setVisible(true);  55 this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  56 this.setSize(500, 380);  57 this.setLocation(500, 200);  58  59 jb1.addActionListener(this);//註冊監聽  60 jb2.addActionListener(this);  61  62 } else {  63  consoleInput();  64  }  65  }  66  67 private void consoleInput() {  68 br = new BufferedReader(new InputStreamReader(System.in));  69 System.out.print("Input:");  70 try {  71 String input = br.readLine();  72 while (!input.equals("q")) {  73 char[] nodes = input.toCharArray();  74 TreeNode treeNode = create(nodes, 0);  75 System.out.println("前序：" + displayPreOrder(treeNode));  76 System.out.println("中序：" + displayInOrder(treeNode));  77 System.out.println("後序：" + displayPostOrder(treeNode));  78 System.out.print("Input:");  79 input = br.readLine();  80  }  81 } catch (IOException e) {  82 try {  83  br.close();  84 } catch (IOException e1) {  85  e1.printStackTrace();  86  }  87  e.printStackTrace();  88  }  89  }  90  91 private TreeNode create(char[] arr, int index) {  92 if (index >= arr.length) // 能夠不須要，可是全部的值必需要寫滿，任一個#都要寫，否則會越界  93 return null;  94 else if (String.valueOf(arr[index]).equals("#")||String.valueOf(arr[index]).equals("*")) {  95 return null;  96 } else {  97 TreeNode node = new TreeNode(arr[index]);  98 node.leftChild = create(arr, 2 * index + 1);  99 node.rightChild = create(arr, 2 * index + 2); 100 return node; 101  } 102  } 103 104 private static String displayInOrder(TreeNode treeNode) { 105 //中序 106 if (treeNode != null) { 107 return displayInOrder(treeNode.leftChild) + (treeNode.data == '*' ? "" : treeNode.data) + 108  displayInOrder(treeNode.rightChild); 109  } 110 return ""; 111  } 112 113 private static String displayPreOrder(TreeNode treeNode) { 114 //前序 115 if (treeNode != null) { 116 return (treeNode.data == '*' ? "" : treeNode.data) + displayPreOrder(treeNode.leftChild) + displayPreOrder(treeNode.rightChild); 117  } 118 return ""; 119  } 120 121 private static String displayPostOrder(TreeNode treeNode) { 122 //中序 123 if (treeNode != null) { 124 return displayPostOrder(treeNode.leftChild) + displayPostOrder(treeNode.rightChild) + (treeNode.data == '*' ? "" : treeNode.data); 125  } 126 return ""; 127  } 128 129  @Override 130 public void actionPerformed(ActionEvent e) { 131 if (e.getSource() == jb1) { 132 String s = jtf.getText(); 133 if (s.matches("[A-Za-z]([A-Za-z]|\\*|#)*")) { //注意：是w就能夠了，不要用/w,就表明字母下劃線 134  myPanel.display(s.toCharArray()); 135 } else { 136 JOptionPane.showMessageDialog(null, "輸入錯誤！\n請重試！","ERROR",JOptionPane.ERROR_MESSAGE); 137 jtf.setText(""); 138  } 139  } 140 else if (e.getSource() == jb2) { 141 jtf.setText(""); 142  } 143  } 144 145 public static void main(String[] args) { 146 new BT(true); 147  } 148 149 class MyPanel extends JPanel implements Runnable { 150  String[] strings; 151 152  MyPanel() { 153 strings = new String[]{"", "", ""}; 154 // this.setSize(100, 1000);//看來絕對佈局裏的setBounds()方法設置的大小具備更高優先級，能夠覆蓋這條設置 155 this.setBackground(new Color(125, 134, 234)); 156  } 157 158 public void display(char[] chars) { 159 TreeNode treeNode = create(chars, 0); 160 strings[0] = displayPreOrder(treeNode); 161 strings[1] = displayInOrder(treeNode); 162 strings[2] = displayPostOrder(treeNode); 163  } 164 165  @Override 166 public void paint(Graphics g) { 167 super.paint(g);// 168 g.setFont(new Font("宋體", Font.BOLD, 24)); 169 g.drawString("前序: " + strings[0], 10, 50); 170 g.drawString("中序: " + strings[1], 10, 100); 171 g.drawString("後序: " + strings[2], 10, 150); 172  } 173 174  @Override 175 public void run() { 176 while (true) { 177 try { 178 Thread.sleep(500); 179  repaint(); 180 } catch (InterruptedException e) { 181  e.printStackTrace(); 182  } 183  } 184  } 185  } 186 187 class TreeNode { 188  Character data; 189  TreeNode leftChild; 190  TreeNode rightChild; 191 //含數據，二叉鏈表 192 TreeNode(char data) { 193 this.data = data; 194 leftChild = null; 195 rightChild = null; 196  } 197  } 198 }