用java实现二叉树

Python020

用java实现二叉树,第1张

我有很多个(假设10万个)数据要保存起来,以后还需要从保存的这些数据中检索是否存在某

个数据,(我想说出二叉树的好处,该怎么说呢?那就是说别人的缺点),假如存在数组中,

那么,碰巧要找的数字位于99999那个地方,那查找的速度将很慢,因为要从第1个依次往

后取,取出来后进行比较。平衡二叉树(构建平衡二叉树需要先排序,我们这里就不作考虑

了)可以很好地解决这个问题,但二叉树的遍历(前序,中序,后序)效率要比数组低很多,

public class Node {

public int value

public Node left

public Node right

public void store(intvalue)

right.value=value

}

else

{

right.store(value)

}

}

}

public boolean find(intvalue)

{

System.out.println("happen" +this.value)

if(value ==this.value)

{

return true

}

else if(value>this.value)

{

if(right ==null)returnfalse

return right.find(value)

}else

{

if(left ==null)returnfalse

return left.find(value)

}

}

public void preList()

{

System.out.print(this.value+ ",")

if(left!=null)left.preList()

if(right!=null) right.preList()

}

public void middleList()

{

if(left!=null)left.preList()

System.out.print(this.value+ ",")

if(right!=null)right.preList()

}

public void afterList()

{

if(left!=null)left.preList()

if(right!=null)right.preList()

System.out.print(this.value+ ",")

}

public static voidmain(String [] args)

{

int [] data =new int[20]

for(inti=0i<data.lengthi++)

{

data[i] = (int)(Math.random()*100)+ 1

System.out.print(data[i] +",")

}

System.out.println()

Node root = new Node()

root.value = data[0]

for(inti=1i<data.lengthi++)

{

root.store(data[i])

}

root.find(data[19])

root.preList()

System.out.println()

root.middleList()

System.out.println()

root.afterList()

}

}

//******************************************************************************************************//

//*****本程序包括简单的二叉树类的实现和前序,中序,后序,层次遍历二叉树算法,*******//

//******以及确定二叉树的高度,制定对象在树中的所处层次以及将树中的左右***********//

//******孩子节点对换位置,返回叶子节点个数删除叶子节点,并输出所删除的叶子节点**//

//*******************************CopyRight By phoenix*******************************************//

//************************************Jan 12,2008*************************************************//

//****************************************************************************************************//

public class BinTree {

public final static int MAX=40

private Object data//数据元数

private BinTree left,right//指向左,右孩子结点的链

BinTree []elements = new BinTree[MAX]//层次遍历时保存各个节点

int front//层次遍历时队首

int rear//层次遍历时队尾

public BinTree()

{

}

public BinTree(Object data)

{ //构造有值结点

this.data = data

left = right = null

}

public BinTree(Object data,BinTree left,BinTree right)

{ //构造有值结点

this.data = data

this.left = left

this.right = right

}

public String toString()

{

return data.toString()

}//前序遍历二叉树

public static void preOrder(BinTree parent){

if(parent == null)

return

System.out.print(parent.data+" ")

preOrder(parent.left)

preOrder(parent.right)

}//中序遍历二叉树

public void inOrder(BinTree parent){

if(parent == null)

return

inOrder(parent.left)

System.out.print(parent.data+" ")

inOrder(parent.right)

}//后序遍历二叉树

public void postOrder(BinTree parent){

if(parent == null)

return

postOrder(parent.left)

postOrder(parent.right)

System.out.print(parent.data+" ")

}// 层次遍历二叉树

public void LayerOrder(BinTree parent)

{

elements[0]=parent

front=0rear=1

while(front<rear)

{

try

{

if(elements[front].data!=null)

{

System.out.print(elements[front].data + " ")

if(elements[front].left!=null)

elements[rear++]=elements[front].left

if(elements[front].right!=null)

elements[rear++]=elements[front].right

front++

}

}catch(Exception e){break}

}

}//返回树的叶节点个数

public int leaves()

{

if(this == null)

return 0

if(left == null&&right == null)

return 1

return (left == null ? 0 : left.leaves())+(right == null ? 0 : right.leaves())

}//结果返回树的高度

public int height()

{

int heightOfTree

if(this == null)

return -1

int leftHeight = (left == null ? 0 : left.height())

int rightHeight = (right == null ? 0 : right.height())

heightOfTree = leftHeight<rightHeight?rightHeight:leftHeight

return 1 + heightOfTree

}

//如果对象不在树中,结果返回-1否则结果返回该对象在树中所处的层次,规定根节点为第一层

public int level(Object object)

{

int levelInTree

if(this == null)

return -1

if(object == data)

return 1//规定根节点为第一层

int leftLevel = (left == null?-1:left.level(object))

int rightLevel = (right == null?-1:right.level(object))

if(leftLevel<0&&rightLevel<0)

return -1

levelInTree = leftLevel<rightLevel?rightLevel:leftLevel

return 1+levelInTree

}

//将树中的每个节点的孩子对换位置

public void reflect()

{

if(this == null)

return

if(left != null)

left.reflect()

if(right != null)

right.reflect()

BinTree temp = left

left = right

right = temp

}// 将树中的所有节点移走,并输出移走的节点

public void defoliate()

{

String innerNode = ""

if(this == null)

return

//若本节点是叶节点,则将其移走

if(left==null&&right == null)

{

System.out.print(this + " ")

data = null

return

}

//移走左子树若其存在

if(left!=null){

left.defoliate()

left = null

}

//移走本节点,放在中间表示中跟移走...

innerNode += this + " "

data = null

//移走右子树若其存在

if(right!=null){

right.defoliate()

right = null

}

}

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

BinTree e = new BinTree("E")

BinTree g = new BinTree("G")

BinTree h = new BinTree("H")

BinTree i = new BinTree("I")

BinTree d = new BinTree("D",null,g)

BinTree f = new BinTree("F",h,i)

BinTree b = new BinTree("B",d,e)

BinTree c = new BinTree("C",f,null)

BinTree tree = new BinTree("A",b,c)

System.out.println("前序遍历二叉树结果: ")

tree.preOrder(tree)

System.out.println()

System.out.println("中序遍历二叉树结果: ")

tree.inOrder(tree)

System.out.println()

System.out.println("后序遍历二叉树结果: ")

tree.postOrder(tree)

System.out.println()

System.out.println("层次遍历二叉树结果: ")

tree.LayerOrder(tree)

System.out.println()

System.out.println("F所在的层次: "+tree.level("F"))

System.out.println("这棵二叉树的高度: "+tree.height())

System.out.println("--------------------------------------")

tree.reflect()

System.out.println("交换每个节点的孩子节点后......")

System.out.println("前序遍历二叉树结果: ")

tree.preOrder(tree)

System.out.println()

System.out.println("中序遍历二叉树结果: ")

tree.inOrder(tree)

System.out.println()

System.out.println("后序遍历二叉树结果: ")

tree.postOrder(tree)

System.out.println()

System.out.println("层次遍历二叉树结果: ")

tree.LayerOrder(tree)

System.out.println()

System.out.println("F所在的层次: "+tree.level("F"))

System.out.println("这棵二叉树的高度: "+tree.height())

}