二叉树的结构分析及实现

来源：互联网发布：淘宝下载到桌面编辑：程序博客网时间：2024/06/05 16:31

二叉树的定义：

    二叉树是每个节点最多只有两个字数的树结构，在图的定义中二叉树是一个连通的无环图，并且每个顶点的度不大于3（根节点的度不大于2）。

二叉树的基本类型：

这里写图片描述

二叉树的实现：

节点结构设计

class Node{        private Object data;        private Node leftChild;        private Node rightChild;        public Node(Object data){            this.data = data;            this.leftChild =null;            this.rightChild = null;        }        public Object getData(){            return this.data;        }        public void setData(Object data) {            this.data = data;        }        public Node getLeftChild() {            return leftChild;        }        public void setLeftChild(Node leftChild) {            this.leftChild = leftChild;        }        public Node getRightChild() {            return rightChild;        }        public void setRightChild(Node rightChild) {            this.rightChild = rightChild;        }    }

2.创建二叉树

public Node createBTree(char[] str){        if(str[i]== '0'){            i++;             return null;        }else {            Node node = new Node(str[i++]);            node.setLeftChild(createBTree(str));            node.setRightChild(createBTree(str));            return node;        }    }

3.遍历二叉树

//先序递归遍历    public void preOrder(Node node){        if(node != null){            System.out.print(node.getData());            preOrder(node.getLeftChild());            preOrder(node.getRightChild());        }    }    //先序非递归遍历    public void nPreOrder(Node node){        Stack<Node> stack = new Stack<Node>();        while(node != null || !stack.isEmpty()){            while(node != null){                System.out.print(node.getData());                stack.push(node);                node = node.getLeftChild();            }            node = stack.pop();            node = node.getRightChild();        }    }    //中序递归遍历    public void inOrder(Node node){        if(node != null){            inOrder(node.getLeftChild());            System.out.print(node.getData());            inOrder(node.getRightChild());        }    }    //中序非递归遍历    public void nInOrder(Node node){        Stack<Node> stack = new Stack<Node>();        while(node != null || !stack.isEmpty()){            while(node != null){                stack.push(node);                node = node.getLeftChild();            }            node = stack.pop();            System.out.print(node.getData());            node = node.getRightChild();        }    }    //后序递归遍历    public void pastOrder(Node node){        if(node != null){            pastOrder(node.getLeftChild());            pastOrder(node.getRightChild());            System.out.print(node.getData());        }    }    //后序非递归遍历    public void nPastOrder(Node node){        Stack<Node> stack = new Stack<Node>();        Node preNode = null;         while(node != null || !stack.isEmpty()){            while(node != null){                stack.push(node);                node = node.getLeftChild();            }            node = stack.peek();            if(node.getRightChild() == null || node.getRightChild() == preNode){                System.out.print(node.getData());                node = stack.pop();                preNode = node;                node = null;            }else{                node = node.getRightChild();            }        }    }

4.测试及输出结果

public static void main(String[] args) {        String str = "ABC00DE00F00G0H00";        BTreeTest bt = new BTreeTest();        root = bt.createBTree(str.toCharArray());        System.out.print("先序递归遍历：");        bt.preOrder(root);        System.out.println();        System.out.print("先序非递归遍历：");        bt.nPreOrder(root);        System.out.println();        System.out.print("中序递归遍历：");        bt.inOrder(root);        System.out.println();        System.out.print("中序非递归遍历：");        bt.nInOrder(root);        System.out.println();        System.out.print("后序递归遍历：");        bt.pastOrder(root);        System.out.println();        System.out.print("后序非递归遍历：");        bt.nPastOrder(root);    }    /**     *输出结果：     *先序递归遍历：ABCDEFGH     *先序非递归遍历：ABCDEFGH     *中序递归遍历：CBEDFAGH     *中序非递归遍历：CBEDFAGH     *后序递归遍历：CEFDBHGA     *后序非递归遍历：CEFDBHGA     */

0 0