[Java] JAVA二叉树的基本操作

• 记录二叉树的基本操作DEMO
  
  
  
  • 1、创建一个二叉树类
    
  • 2、然后创建二叉树的节点
    
  
  

/**
 * @author JackHui
 * @version BinaryTree.java, 2020年03月05日 12:45
 */
public class BinaryTree<T extends Comparable> {
 
  //树根
  BinaryTreeNode root;
 
  public boolean deleteData(T data) {
    if (root.data.equals(data)) {
      root = null;
      return true;
    }
    return root.deleteNode(data);
  }
 
  public T frontSearch(T data) {
    return (T) root.frontSearch(data);
  }
 
  public T midSearch(T data) {
    return (T) root.midSearch(data);
  }
 
  public T rearSearch(T data) {
    return (T) root.rearSearch(data);
  }
 
  public void frontEach() {
    this.root.frontEach();
  }
 
  public void midEach() {
    this.root.midEach();
  }
 
  public void rearEach() {
    this.root.rearEach();
  }
 
 
  public BinaryTreeNode getRoot() {
    return root;
  }
 
  public void setRoot(BinaryTreeNode root) {
    this.root = root;
  }
}

package binarytree;
 
/**
 * @author JackHui
 * @version BinaryTreeNode.java, 2020年03月06日 10:24
 */
public class BinaryTreeNode<T extends Comparable> {
  T data;
  BinaryTreeNode lChild;
  BinaryTreeNode rChild;
 
  public BinaryTreeNode(T data) {
    this.data = data;
  }
 
  //先序遍历
  public void frontEach() {
    System.out.print(this.data + "\t");
    if (lChild != null) {
      lChild.frontEach();
    }
    if (rChild != null) {
      rChild.frontEach();
    }
  }
 
  //中序遍历
  public void midEach() {
    if (lChild != null) {
      lChild.frontEach();
    }
    System.out.print(this.data + "\t");
    if (rChild != null) {
      rChild.frontEach();
    }
  }
 
  //后序遍历
  public void rearEach() {
    if (lChild != null) {
      lChild.frontEach();
    }
    if (rChild != null) {
      rChild.frontEach();
    }
    System.out.print(this.data + "\t");
  }
 
  //先序查找
  public T frontSearch(T data) {
    T target = null;
    System.out.println("[先序遍历]当前遍历到的元素:" + this.data + "\t查找的元素:" + data + "\t" + (this.data.compareTo(data) == 0 ? "查找到元素:" + data : ""));
    if (this.data.compareTo(data) == 0) {
      return data;
    } else {
      if (lChild != null && (target = (T) lChild.frontSearch(data)) != null) {
        return target;
      }
      if (rChild != null && (target = (T) rChild.frontSearch(data)) != null) {
        return target;
      }
    }
    return target;
  }
 
  //中序查找
  public T midSearch(T data) {
    T target = null;
    if (lChild != null && (target = (T) lChild.midSearch(data)) != null) {
      return target;
    }
    System.out.println("[中序遍历]当前遍历到的元素:" + this.data + "\t查找的元素:" + data + "\t" + (this.data.compareTo(data) == 0 ? "查找到元素:" + data : ""));
    if (this.data.compareTo(data) == 0) {
      return data;
    } else {
      if (rChild != null && (target = (T) rChild.midSearch(data)) != null) {
        return target;
      }
    }
    return target;
  }
 
  //后序查找
  public T rearSearch(T data) {
    T target = null;
    if (lChild != null && (target = (T) lChild.rearSearch(data)) != null) {
      return target;
    }
    if (rChild != null && (target = (T) rChild.rearSearch(data)) != null) {
      return target;
    }
    System.out.println("[后续遍历]当前遍历到的元素:" + this.data + "\t查找的元素:" + data + "\t" + (this.data.compareTo(data) == 0 ? "查找到元素:" + data : ""));
    if (this.data.compareTo(data) == 0) {
      return data;
    }
    return target;
  }
 
  //根据值删除节点
  public boolean deleteNode(T data) {
    System.out.println("[节点删除]当前遍历到的父节点:" + this.data + "\t" + "匹配的节点数据:" + data);
    //判断左子树是否匹配
    if (this.lChild != null && (this.lChild.data.compareTo(data) == 0)) {
      System.out.println("[节点删除]当前遍历到的父节点:" + this.data + "\t" + "匹配的节点数据:" + data + "\t节点删除成功!");
      this.lChild = null;
      return true;
    } else if (this.rChild != null && (this.rChild.data.compareTo(data) == 0)) {
      System.out.println("[节点删除]当前遍历到的父节点:" + this.data + "\t" + "匹配的节点数据:" + data + "\t节点删除成功!");
      this.rChild = null;
      return true;
    }
    if (this.lChild != null && this.lChild.deleteNode(data)) {
      return true;
    }
    if (this.rChild != null && this.rChild.deleteNode(data)) {
      return true;
    }
    return false;
  }
 
  public T getData() {
    return data;
  }
 
  public void setData(T data) {
    this.data = data;
  }
 
  public BinaryTreeNode getlChild() {
    return lChild;
  }
 
  public void setlChild(BinaryTreeNode lChild) {
    this.lChild = lChild;
  }
 
  public BinaryTreeNode getrChild() {
    return rChild;
  }
 
  public void setrChild(BinaryTreeNode rChild) {
    this.rChild = rChild;
  }
}