java 二叉查找树实例代码

public class BinaryTree {  // 二叉树的根节点  public TreeNode rootNode ;  // 记录搜索深度  public int count;  /**   * 利用传入一个数组来建立二叉树   */  public BinaryTree(int[] data) {    for (int i = 0; i < data. length; i++) {      addNodeToTree(data[i]);    }  }  /**   * 将指定的值加入到二叉树中适当的节点   */  private void addNodeToTree(int value) {    TreeNode currentNode = rootNode;    // 建立树根    if (rootNode == null) {      rootNode = new TreeNode(value);      return;    }    // 建立二叉树    while (true) {      // 新增的value比节点的value小，则在左子树      if (value < currentNode.value ) {        if (currentNode.leftNode == null) {          currentNode.leftNode = new TreeNode(value);          return;        } else {          currentNode = currentNode.leftNode;        }      } else { // 新增的value比节点的value大，在右子树        if (currentNode.rightNode == null) {          currentNode. rightNode = new TreeNode(value);          return;        } else {          currentNode = currentNode. rightNode;        }      }    }  }  /**   * 中序遍历(左子树 -树根- 右子树)   */  public void inOrder(TreeNode node) {    if (node != null) {      inOrder(node. leftNode);      System. out.print("[" + node.value + "]");      inOrder(node. rightNode);    }  }  /**   * 前序遍历(树根 -左子树- 右子树)   */  public void preOrder(TreeNode node) {    if (node != null) {      System. out.print("[" + node.value + "]");      preOrder(node. leftNode);      preOrder(node. rightNode);    }  }  /**   * 后序遍历(左子树 -右子树- 树根)   */  public void postOrder(TreeNode node) {    if (node != null) {      postOrder(node. leftNode);      postOrder(node. rightNode);      System. out.print("[" + node.value + "]");    }  }  /**   * 从二叉树中查找指定value   */  public boolean findTree(TreeNode node, int value) {    if (node == null) {      System. out.println("共搜索" + count + "次");      return false;    } else if (node.value == value) {      System. out.println("共搜索" + count + "次");      return true;    } else if (value < node.value) {      count++;      return findTree(node.leftNode , value);    } else {      count++;      return findTree(node.rightNode , value);    }  }  /**   * 利用中序遍历进行排序   */  public void sort() {    this.inOrder(rootNode );  }  class TreeNode {    int value ;    TreeNode leftNode;    TreeNode rightNode;    public TreeNode(int value) {      this.value = value;      this.leftNode = null;      this.rightNode = null;    }  }  public static void main(String[] args) {    int[] content = { 50, 35, 27, 45, 40, 48, 78, 56, 90 };    BinaryTree tree = new BinaryTree(content);    System. out.println("前序遍历:" );    tree.preOrder(tree. rootNode);    System. out.println("/n中序遍历:" );    tree.inOrder(tree. rootNode);    System. out.println("/n后序遍历:" );    tree.postOrder(tree. rootNode);    System. out.println("/n/n开始搜索:" );    boolean isFind = tree.findTree(tree.rootNode, 48);    System. out.println("是否搜索到" + 48 + ":" + isFind);    System. out.println("/n进行排序:" );    tree.sort();  }}

[50][35][27][45][40][48][78][56][90]

[27][35][40][45][48][50][56][78][90]

[27][40][48][45][35][56][90][78][50]

[27][35][40][45][48][50][56][78][90]