二叉树的JAVA实现-二叉树的增删改查CRUD

package org.lyk.interfaces;

import java.util.List;

public interface IBiTree<T extends Comparable<T>>
{
    public void addWithOrder(T data);
    public void addFirst(T[] data,T endFlag);
    public Object[] toArrayFirst();
    public Object[] toArrayMiddle();
    public Object[] toArrayLast();
    public int size();
    public boolean isEmpty();
    public boolean contains(T data);
    public void delete(T data);
}

package org.lyk.entities;

import java.util.HashMap;
import java.util.Map;

import org.lyk.interfaces.IBiTree;

public class BiTree<T extends Comparable<T>> implements IBiTree<T>
{
    private class Node<N extends Comparable<N>>
    {
        private N data;
        private Node<N> left;
        private Node<N> right;

        private Node(N data)
        {
            if (null == data)
                return;
            this.data = data;
        }

        public void addWithOrder(N data)
        {
            // if(this.data.compareTo(data) < 0)
            if (data.compareTo(this.data) < 0)
            {
                if (null == this.left)
                {
                    this.left = new Node<N>(data);
                    BiTree.this.count++;
                } else
                    this.left.addWithOrder(data);
            } else
            {
                if (null == this.right)
                {
                    this.right = new Node<N>(data);
                    BiTree.this.count++;
                } else
                    this.right.addWithOrder(data);
            }
        }

        public void toArrayFirst(Object[] retVal)
        {
            retVal[BiTree.this.foot++] = this.data;
            if (null != this.left)
                this.left.toArrayFirst(retVal);
            if (null != this.right)
                this.right.toArrayFirst(retVal);
        }

        public void toArrayMiddle(Object[] retVal)
        {
            if (null != this.left)
                this.left.toArrayMiddle(retVal);
            retVal[BiTree.this.foot++] = this.data;
            if (null != this.right)
                this.right.toArrayMiddle(retVal);
        }

        public void toArrayLast(Object[] retVal)
        {
            if (null != this.left)
                this.left.toArrayLast(retVal);
            if (null != this.right)
                this.right.toArrayLast(retVal);
            retVal[BiTree.this.foot++] = this.data;
        }
    }

    private int count = 0;
    private Node<T> root = null;
    private int foot = 0;

    @Override
    public void addWithOrder(T data)
    {
        if (null == data)
            return;

        if (null == this.root)
        {
            this.root = new Node<T>(data);
            this.count++;
        } else
        {
            this.root.addWithOrder(data);
        }
    }

    @Override
    public void addFirst(T[] data, T endFlag)
    {
        if (null == data)
        {
            return;
        }

        this.foot = 0;
        this.root = this.addFirstInternal(data, endFlag, this.root);
    }

    private Node<T> addFirstInternal(T[] data, T endFlag, Node<T> node)
    {
        if (data[this.foot].equals(endFlag))
        {
            this.foot++;
            return null;
        } else
        {
            node.data = data[this.foot];
            this.foot++;
            node.left = this.addFirstInternal(data, endFlag, node.left);
            node.right = this.addFirstInternal(data, endFlag, node.right);
            return node;
        }
    }

    @Override
    public Object[] toArrayFirst()
    {
        if (this.isEmpty())
            return null;
        Object[] retVal = new Object[this.count];
        this.foot = 0;
        this.root.toArrayFirst(retVal);
        return retVal;
    }

    @Override
    public Object[] toArrayMiddle()
    {
        if (this.isEmpty())
            return null;
        Object[] retVal = new Object[this.count];
        this.foot = 0;
        this.root.toArrayMiddle(retVal);
        return retVal;
    }

    @Override
    public Object[] toArrayLast()
    {
        if (this.isEmpty())
            return null;
        Object[] retVal = new Object[this.count];
        this.foot = 0;
        this.root.toArrayLast(retVal);
        return retVal;
    }

    @Override
    public int size()
    {
        return this.count;
    }

    @Override
    public boolean isEmpty()
    {
        if (0 == this.count && null == this.root)
            return true;
        else
            return false;
    }

    @Override
    public void delete(T data)
    {
        if (this.isEmpty())
            return;

        Map<String, Object> nodeDel = this.find(data);
        if (null == nodeDel)
            return;

        Node<T> node = (Node<T>) nodeDel.get("node");
        Node<T> parent = (Node<T>) nodeDel.get("parent");
        String direction = (String) nodeDel.get("direction");
        if (null == node.left && null == node.right)
        {
            if (null == direction)
            {
                this.root = null;
            } else
            {
                if ("left".equals(direction))
                {
                    parent.left = null;
                } else if ("right".equals(direction))
                {
                    parent.right = null;
                }
            }
            this.count--;
            return;
        }

        if (null != node.left && null == node.right)
        {
            // 该节点只有左子树
            if (null == direction)
            {
                Node<T> temp = this.root;
                this.root = this.root.left;
                temp.left = null;
            } else
            {
                if ("left".equals(direction))
                {
                    parent.left = node.left;
                    node.left = null;
                } else if ("right".equals(direction))
                {
                    parent.right = node.left;
                    node.left = null;
                }
            }
            this.count--;
            return;
        }

        if (null == node.left && null != node.right)
        {
            // 该节点只有右子树
            if (null == direction)
            {
                Node<T> temp = this.root;
                this.root = this.root.right;
                temp.right = null;
            } else
            {
                if ("left".equals(direction))
                {
                    parent.left = node.right;
                    node.right = null;
                } else if ("right".equals(direction))
                {
                    parent.right = node.right;
                    node.right = null;
                }
            }
            this.count--;
            return;
        }

        Node<T> subsessor = this.getSubsessor(node);
        if (null != subsessor)
        {
            //System.out.println("subsessor:" + subsessor.data);
            subsessor.left = node.left;
            if (null == direction)
            {
                this.root = subsessor;
            } else if ("left".equals(direction))
            {
                parent.left = subsessor;
            } else if ("right".equals(direction))
            {
                parent.right = subsessor;
            }
            this.count--;
        }
        
    }

    private Node<T> getSubsessor(Node<T> nodeDel)
    {
        Node<T> parent = nodeDel;
        Node<T> subsessor = nodeDel.right;
        subsessor = this.getSubsessorInternal(parent, subsessor, nodeDel);
        return subsessor;
    }

    private Node<T> getSubsessorInternal(Node<T> parent, Node<T> subsessor, Node<T> nodeDel)
    {
        if (null != subsessor.left)
        {
            parent = subsessor;
            subsessor = subsessor.left;
            return getSubsessorInternal(parent, subsessor, nodeDel);
        } else
        {
            if (subsessor != nodeDel.right)
            {
                parent.left = subsessor.right;
                subsessor.right = nodeDel.right;
            }
            return subsessor;
        }
    }

    private Map<String, Object> find(T data)
    {
        return this.findInternal(this.root, null, null, data);
    }

    private Map<String, Object> findInternal(Node<T> node, Node<T> parent, String direction, T data)
    {
        Map<String, Object> retVal = null;
        if (node.data.equals(data))
        {
            retVal = new HashMap<>();
            retVal.put("node", node);
            retVal.put("parent", parent);
            retVal.put("direction", direction); 
            return retVal;
        } else
        {
            if (null != node.left)
            {
                // parent = node;
                // node = node.left;
                retVal = this.findInternal(node.left, node, "left", data);
                if(null != retVal)
                    return retVal;
            }

            if (null != node.right)
            {
                // parent = node;
                // node = node.right;
                retVal = this.findInternal(node.right, node, "right", data);
                if(null != retVal)
                    return retVal;
            }
        }
        return retVal;
    }

    @Override
    public boolean contains(T data)
    {
        // TODO Auto-generated method stub
        return false;
    }

}