原创误删，写了个N叉树，格式输出了下二叉树，抛砖引玉而已， 求各种实现方式

package org.benson.dto;



import java.util.ArrayList;

import java.util.List;



/**

 * @author BenSon He

 * @email [email protected] ,qq 107966750

 * @since 19/21/2012

 */

public class Node {

	List<Node> list = new ArrayList<Node>();;

	private int value;

	private int level;



	public int getLevel() {

		return level;

	}



	public void setLevel(int level) {

		this.level = level;

	}



	public Node getNodeByIndex(int index) {

		return list.get(index);

	}



	public void addNode(Node node) {

		list.add(node);

	}



	public int getValue() {

		return value;

	}



	public void setValue(int value) {

		this.value = value;

	}



	public int getSize() {

		return list.size();

	}



}

　　

package org.benson.util;



import org.benson.dto.Node;

/**

 * @author BenSon He

 * @email [email protected] ,qq 107966750

 * @since 19/21/2012

 */

public class XTreeUtil {

	static int index;

	static String toStrArray[][];



	public static void getXTree(Node node, int level, int nx) {

		level--;

		index = node.getValue();

		for (int i = 0; i <= nx; i++) {

			// index=index+1;

			// System.out.println(index);

			Node chirdNode = new Node();

			chirdNode.setValue(++index);

			node.addNode(chirdNode);

			node.setLevel(level);

			if (level > 0)

				getXTree(chirdNode, level, nx);

		}

	}



	/**

	 * get node by level and index

	 * 

	 * @param node

	 *            , start of node

	 * @param level

	 * @param index

	 *            , the index of chirdNode

	 * @return

	 */

	public static Node getNode(Node node, int level, int index) {

		level--;

		if (level > 0)

			return getNode(node.getNodeByIndex(index), level, index);

		else

			return node.getNodeByIndex(index);

	}



	public static void displayTree(Node node, int level, int nx) {

		int indexLenth = getNode(node, level, nx).getValue() + 1;

		toStrArray = new String[level+1][indexLenth];

		// init array

		for (int i = 0; i < toStrArray.length; i++) {

			for (int j = 0; j < toStrArray[i].length; j++) {

				toStrArray[i][j]=" ";

			}

		}

		toStrArray[level][toStrArray[0].length/2]=String.valueOf(node.getValue());

		fillTree(node, level, toStrArray[0].length/2);

		for (int i = 0; i < toStrArray.length; i++) {

			for (int j = 0; j < toStrArray[i].length; j++) {

				System.out.print(toStrArray[i][j]);

			}

			System.out.println();

		}

		System.out.println();

	}

	public static void fillTree(Node node,int level,int index){

		level--;

		int spaceCount=(int) Math.pow(2, level);

		Node leftNode=node.getNodeByIndex(0);

		toStrArray[level][index+spaceCount]=String.valueOf(leftNode.getValue());

		Node rightNode=node.getNodeByIndex(1);

		toStrArray[level][index-spaceCount]=String.valueOf(rightNode.getValue());

		if(level>0){

			fillTree(leftNode, level, index+spaceCount);

			fillTree(rightNode, level, index-spaceCount);

			}

		

	}



	public static void main(String[] args) {

		Node node = new Node();

		int level=4;

		int nIndex=1; // start with 0. 1 is 2 leaf

		node.setValue(1);// start value . root value

		XTreeUtil.getXTree(node, level, nIndex); // level and index .the level start element index is 0

		displayTree(node,level, nIndex);

	}

}

输出如下

 31 30 28 27 24 23 21 20 16 15 13 12 9 8 6 5

  29   26   22   19   14   11   7   4 

    25       18       10       3   

        17               2       

                1               

　　

可以改变nIndex实现N叉树结构

nIndex=1  二叉

nIndex= 2  三叉

只做了二叉的格式化输出，但是N叉格式化输出就没做了，觉得还是有点麻烦

 

写着玩而已，没去查其他实现，或许有BUG，求指出。

不喜勿喷

如果有兴趣贴上各种实现方式

 

 

类似应用，比如生成XML的递归 也不错

当然，递归在时间和空间上都不怎么好

View Code

package org.benson.another;



import java.util.ArrayList;

import java.util.List;



/**

 * 

 * @author BensonHe QQ277803242

 * 

 *         TODO manage node and value.and format the node to xml file

 * 

 */

public class XMLSimpleNode implements SimpleNode {

    private String nodeName;

    private String value;

    List<SimpleNode> childs;

    private String header;



    public XMLSimpleNode(String nodeName) {

        this.nodeName = nodeName;

        childs = new ArrayList<SimpleNode>(2);

    }



    public String getNodeName() {

        return nodeName;

    }



    /*

     * (non-Javadoc)

     * 

     * @see org.benson.another.SimpleXMLFileUtil#setNodeName(java.lang.String)

     */

    public void setNodeName(String nodeName) {

        this.nodeName = nodeName;

    }



    public String getValue() {

        return value;

    }



    /*

     * (non-Javadoc)

     * 

     * @see org.benson.another.SimpleXMLFileUtil#setValue(java.lang.String)

     */

    public void setValue(String value) {

        this.value = value;

    }



    /*

     * (non-Javadoc)

     * 

     * @see org.benson.another.SimpleXMLFileUtil#addChild(org.benson.another.XMLItem)

     */

    public void addChild(SimpleNode node) {

        childs.add(node);

    }



    public String startTag() {

        StringBuffer tagSart = new StringBuffer("<");

        tagSart.append(nodeName);

        tagSart.append(">");

        return tagSart.toString();

    }



    public String endTag() {

        StringBuffer tagEnd = new StringBuffer("</");

        tagEnd.append(nodeName);

        tagEnd.append(">");

        return tagEnd.toString();

    }



    public String getHeader() {

        return header;

    }



    /*

     * (non-Javadoc)

     * 

     * @see org.benson.another.SimpleXMLFileUtil#setHeader(java.lang.String)

     */

    public void setHeader(String header) {

        this.header = header;

    }



    /**

     * ToDo format the node to xml file

     */

    public String formartXMLFile() {

        StringBuffer xmlFileBf = new StringBuffer();

        xmlFileBf.append(this.getHeader());

        return this.getNode(this, xmlFileBf).toString();

    }



    /**

     * 

     * @param node

     * @param xmlFileBf

     * @return get XML content by node

     */

    private StringBuffer getNode(SimpleNode node, StringBuffer xmlFileBf) {

        XMLSimpleNode xmlNode = (XMLSimpleNode) node;

        XMLSimpleNode xmlNodeItem = null;

        xmlFileBf.append(xmlNode.startTag());

        if (xmlNode.childs.size() != 0) {

            for (int i = 0; i < xmlNode.childs.size(); i++) {

                xmlNodeItem = (XMLSimpleNode) xmlNode.childs.get(i);

                getNode(xmlNodeItem, xmlFileBf);

            }

        }

        if (xmlNode.getValue() != null)

            xmlFileBf.append(xmlNode.getValue());

        xmlFileBf.append(xmlNode.endTag());

        return xmlFileBf;

    }



    public static void main(String[] args) {

        SimpleNode xmlNode = new XMLSimpleNode("root");

        xmlNode.setHeader("<?xml version=\"1.0\" encoding=\"UTF-8\" ?> ");

        SimpleNode chridNode1 = new XMLSimpleNode("chrid1");

        SimpleNode chridNode2 = new XMLSimpleNode("chrid2");

        SimpleNode chridNode3 = new XMLSimpleNode("chrid3");

        SimpleNode chridNode11 = new XMLSimpleNode("chrid11");

        SimpleNode chridNode12 = new XMLSimpleNode("chrid12");

        SimpleNode chridNode13 = new XMLSimpleNode("chrid13");

        chridNode11.setValue("chridNode11 Value");

        chridNode12.setValue("chridNode12 Value");

        chridNode13.setValue("chridNode13 Value");

        chridNode2.setValue("chridNode2 Value");

        chridNode3.setValue("chridNode3 value");

        chridNode1.addChild(chridNode11);

        chridNode1.addChild(chridNode12);

        chridNode1.addChild(chridNode13);

        xmlNode.addChild(chridNode1);

        xmlNode.addChild(chridNode2);

        xmlNode.addChild(chridNode3);

        System.out.println(xmlNode.formartXMLFile());

    }





}

输出效果如下

<?xml version="1.0" encoding="UTF-8" ?> <root><chrid1><chrid11>chridNode11 Value</chrid11><chrid12>chridNode12 Value</chrid12><chrid13>chridNode13 Value</chrid13></chrid1><chrid2></chrid2><chrid3></chrid3></root>