bitree.java.txt

数据结构 二叉树 的java实现 简单易懂

//******************************************************************************************************//
//*****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
private Object data; //数据元数
private BinTree left,right; //指向左,右孩子结点的链

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=0;rear=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()
{
   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...
   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());
}