二叉树的先序创建，先序，中序，后序的递归与非递归遍历，层次遍历，叶子结点数及树的深度

二叉树的先序创建，先序，中序，后序的递归与非递归遍历，层次遍历，叶子结点数及树的深度计算

输入格式：如   abd###ce##f##*

 

package tree;
//二叉树的二叉链表实现

import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import java.util.Stack;


public class BTree<AnyType> {

	BTNode rootNode=new BTNode();
	
	  class BTNode<AnyType>{
		char data;
		BTNode<AnyType> leftChildNode;
		BTNode<AnyType> rightChildNode;
		public BTNode(){
			data=0;
			leftChildNode=rightChildNode=null;
		}
		public BTNode(char data){
			this.data=data;
			leftChildNode=rightChildNode=null;
		}
		public BTNode(char data,BTNode leftChildNode,BTNode rightChildNode){
			this.data=data;
			leftChildNode=leftChildNode;
			rightChildNode=rightChildNode;
		}
	}

	 //先序创建二叉树
        char d[]=new char[100];
		int i=0;
		public BTNode creatBTree(){
			BTNode node=null;
		    if(d[i]!='*'){
			    if(d[i]=='#'){
				    node=null;
				    i++;
			    }
			    else{
				    node=new BTNode(d[i]);
				    i++; 
				    node.leftChildNode=creatBTree();   
				    node.rightChildNode=creatBTree();			
			}
			}
			return node;
		}

	//先序递归遍历
	public void preOrder(BTNode<AnyType> t){
		if(t!=null){
			System.out.print(t.data);
			preOrder(t.leftChildNode);
			preOrder(t.rightChildNode);
		}
	}
	//先序非递归遍历
	public void preStackOrder(BTNode t){
		Stack s=new Stack();
		BTNode p=t;
		while(p!=null&&s.isEmpty()!=true){
			if(p!=null){
				System.out.print(p.data);
				s.push(p);
				p=p.leftChildNode;
			}
			if(s.isEmpty()){
				s.pop();
				p=p.rightChildNode;
			}
		}
	}
	//中序递归遍历
	public void inOrder(BTNode t){
		if(t!=null){
			inOrder(t.leftChildNode);
			System.out.print(t.data);
			inOrder(t.rightChildNode);
		}
		
	}
	//中序非递归遍历
    public void inStackOrder(BTNode t){
  
    	Stack<BTNode> s=new Stack<BTNode>();
    	BTNode p=t;
    	while(p!=null&&s.isEmpty()){
    		if(p!=null){
    			s.push(p);
    			p=p.leftChildNode;
    		}
    		if(s.isEmpty()!=true){
    			p=s.pop();
    			System.out.print(p.data);
    			p=p.rightChildNode;
    		}
    	}
    }
	//后序递归遍历
	public void postOrder(BTNode t){
		if(t!=null){
			postOrder(t.leftChildNode);
			postOrder(t.rightChildNode);
			System.out.print(t.data);
		}
	}
	//后序非递归遍历
	public void postStackOrder(BTNode t){
		Stack<BTNode> s=new Stack<BTNode>();
		Stack<Integer> ss=new Stack<Integer>();
        Integer i=new Integer(1);
		BTNode p=t;
		BTNode q=t;
		while(p!=null||s.isEmpty()!=true){	
			while(p!=null){
				s.push(p);
				ss.push(new Integer(0));
				p=p.leftChildNode;	
			}
			while(s.isEmpty()!=true&&ss.peek().equals(i)){
				ss.pop();
				q=s.pop();
				System.out.print(q.data);	
			}
			if(s.isEmpty()!=true){
				ss.pop();
				ss.push(i);
				p=s.peek();
				p=p.rightChildNode;	
			}	
		}	
	}
     //层次非递归遍历
	public void levelQueueOrder(BTNode t){
		Queue<BTNode> q=new LinkedList<BTNode>();
		q.add(t);
		while(q.isEmpty()!=true){
			BTNode step=q.remove();
			System.out.print(step.data);
			if(step.leftChildNode!=null){
				q.add(step.leftChildNode);
			}
			if(step.rightChildNode!=null){
				q.add(step.rightChildNode);
			}
		}
	}
	//计算二叉树深度
	public int depth(BTNode t){
		int leftDepth,rightDepth;
		if(t==null) 
			return 0;
		leftDepth=depth(t.leftChildNode);
		rightDepth=depth(t.rightChildNode);
		return Math.max(leftDepth,rightDepth)+1;
	}
	
	//叶子结点个数
	int num=0;
	public int leaf(BTNode t){
		if(t!=null){
			if(t.leftChildNode==null&&t.rightChildNode==null)
				num++;
		    leaf(t.leftChildNode);
		    leaf(t.rightChildNode);
		}
		return num;
	}
	
	public static void main(String[] args) {
	    BTree bt=new BTree();
		Scanner sc=new Scanner(System.in);
		String a=sc.next();
		char c[]=a.toCharArray();
		for(int i=0;i<c.length;i++){
		     bt.d[i]=c[i];
		}
		bt.rootNode=bt.creatBTree();
		System.out.println("先序遍历");
		bt.preOrder(bt.rootNode);
		System.out.println();
		System.out.println("中序遍历");
		bt.inOrder(bt.rootNode);
		System.out.println();
		System.out.println("后序遍历");
		bt.postOrder(bt.rootNode);
		System.out.println();
		System.out.println("后序非递归遍历");
		bt.postStackOrder(bt.rootNode);
		System.out.println("层次遍历");
		bt.levelQueueOrder(bt.rootNode);
		System.out.println();
		System.out.println("二叉树深度");
		System.out.println(bt.depth(bt.rootNode));
		System.out.println("叶子结点个数");
		System.out.println(bt.leaf(bt.rootNode));
	}

}