复制代码 代码如下:

#!/usr/bin/python

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

class TreeNode(object):

def __init__(self,data=0,left=0,right=0):

self.data = data

self.left = left

self.right = right

class BTree(object):

def __init__(self,root=0):

self.root = root

def is_empty(self):

if self.root is 0:

return True

else:

return False

def preOrder(self,treenode):

if treenode is 0:

return

print treenode.data

self.preOrder(treenode.left)

self.preOrder(treenode.right)

def inOrder(self,treenode):

if treenode is 0:

return

self.inOrder(treenode.left)

print treenode.data

self.inOrder(treenode.right)

def postOrder(self,treenode):

if treenode is 0:

return

self.postOrder(treenode.left)

self.postOrder(treenode.right)

print treenode.data

n1 = TreeNode(data=1)

n2 = TreeNode(2,n1,0)

n3 = TreeNode(3)

n4 = TreeNode(4)

n5 = TreeNode(5,n3,n4)

n6 = TreeNode(6,n2,n5)

n7 = TreeNode(7,n6,0)

n8 = TreeNode(8)

root = TreeNode('root',n7,n8)

bt = BTree(root)

print 'preOrder......'

print bt.preOrder(bt.root)

print 'inOrder......'

print bt.inOrder(bt.root)

print 'postOrder.....'

print bt.postOrder(bt.root)

结果：

preOrder......

root

7

6

2

1

5

3

4

8

inOrder......

1

2

6

3

5

4

7

root

8

postOrder.....

1

2

3

4

5

6

7

8

root