【DataStructure】Implemantation of Binary Tree

标签：datastructure   java   

Statements: This blog was written by me, but most of content  is quoted from book【Data Structure with Java Hubbard】 

Here is a class for binary trees that directly implements the recursive definition. By extending the AbstractCollectionclass, it remains consistent with the Java Collections Framework.

【Implementation】

package com.albertshao.ds.tree;

//  Data Structures with Java, Second Edition
//  by John R. Hubbard
//  Copyright 2007 by McGraw-Hill

import java.util.*;

public class BinaryTree<E> extends AbstractCollection {
  protected E root;
  protected BinaryTree<E> left, right, parent;
  protected int size;
  
  public BinaryTree() {
  }
  
  public BinaryTree(E root) {
    this.root = root;
    size = 1;
  }
  
  public BinaryTree(E root, BinaryTree<E> left, BinaryTree<E> right) {
    this(root);
    if (left != null) {
      this.left = left;
      left.parent = this;
      size += left.size();
    }
    if (right != null) {
      this.right = right;
      right.parent = this;
      size += right.size();
    }
  }

  public boolean equals(Object object) {
    if (object == this) {
      return true;
    } else if (!(object instanceof BinaryTree)) {
      return false;
    }
    BinaryTree that = (BinaryTree)object;
    return that.root.equals(this.root)
        && that.left.equals(this.left)
        && that.right.equals(this.right)
        && that.parent.equals(this.parent)
        && that.size == this.size;
  }

  public int hashCode() {
    return root.hashCode() + left.hashCode() + right.hashCode() + size;
  }
  
  public int size() {
    return size;
  }

  public Iterator iterator() {
    return new java.util.Iterator() { // anonymous inner class
      private boolean rootDone;
      private Iterator lIt, rIt;  // child iterators
      public boolean hasNext() {
        return !rootDone || lIt != null && lIt.hasNext()
                         || rIt != null && rIt.hasNext();
      }
      public Object next() {
        if (rootDone) {
          if (lIt != null && lIt.hasNext()) {
            return lIt.next();
          }
          if (rIt != null && rIt.hasNext()) {
            return rIt.next();
          }
          return null;
        }
        if (left != null) {
          lIt = left.iterator();
        }
        if (right != null) {
          rIt = right.iterator();
        }
        rootDone = true;
        return root;
      }
      public void remove() {
        throw new UnsupportedOperationException(); 
      }
    };
  }
}

package com.albertshao.ds.tree;

//  Data Structures with Java, Second Edition
//  by John R. Hubbard
//  Copyright 2007 by McGraw-Hill


public class TestBinaryTree {
  static public void main(String[] args) {
    BinaryTree<String> e = new BinaryTree<String>("E");
    BinaryTree<String> g = new BinaryTree<String>("G");
    BinaryTree<String> h = new BinaryTree<String>("H");
    BinaryTree<String> i = new BinaryTree<String>("I");
    BinaryTree<String> d = new BinaryTree<String>("D", null, g);
    BinaryTree<String> f = new BinaryTree<String>("F", h, i);
    BinaryTree<String> b = new BinaryTree<String>("B", d, e);
    BinaryTree<String> c = new BinaryTree<String>("C", f, null);
    BinaryTree<String> tree = new BinaryTree<String>("A", b, c);
    System.out.printf("tree: %s", tree);
  }
}

【Result】

tree: [A, B, D, G, E, C, F, H, I]

The example shows two views of the same tree. The larger view shows all the details, representing each
object reference with an arrow.

【DataStructure】Implemantation of Binary Tree,布布扣,bubuko.com

【DataStructure】Implemantation of Binary Tree

标签：datastructure   java   

原文地址：http://blog.csdn.net/sxb0841901116/article/details/38689679