用python实现二叉树结构

实现：

1、定义二叉树，二叉树的根节点值大于左子树节点值，小于右子树节点值

2、节点插入，每个子树相当与一个节点，节点拥有左节点和右节点

3、二叉树的前序，中序，后序遍历

#-*-coding:utf-8-*-

class Node:
    def __init__(self, data):
        self.root = data
        self.left_node = None
        self.right_node = None


class binaryTree:

    def __init__(self):
        self.tree = None;

    def addNode(self, data, currt_node):
        node = Node(data)
        if self.tree is None:
            self.tree = node

        else:
            if currt_node.root > data:
                if currt_node.left_node is None:
                    currt_node.left_node = node
                else:
                    self.addNode(data, currt_node.left_node)
            else:
                if currt_node.right_node is None:
                    currt_node.right_node = node
                else:
                    self.addNode(data, currt_node.right_node)

    def preorder(self, tree):  # 先序遍历
        if tree.root is not None:
            #先序遍历
            #print(tree.root)
            if tree.left_node is not None:
                self.preorder(tree.left_node)
            #中序遍历
            print(tree.root)

            if tree.right_node is not None:
                self.preorder(tree.right_node)
            #后序遍历
            #print(tree.root)



if __name__ == '__main__':
    btree = binaryTree()

    btree.addNode(5, btree.tree)
    btree.addNode(3, btree.tree)
    btree.addNode(7, btree.tree)
    btree.addNode(4, btree.tree)
    btree.addNode(8, btree.tree)
    btree.addNode(6, btree.tree)

    btree.preorder(btree.tree)