python 写二叉树遍历

zrong

在http://www.python.org/下载了编译器，很方便、好用

#树节点类----------------------------------------
class TreeNode(object):
#初始化构造函数
def __init__(self,data,left,right):
self.data=data
self.left=left
self.right=right
pass
pass
#树----------------------------------------------
class Tree(object):
#获取树
def get(self):
n9=TreeNode('n9','','')
n8=TreeNode('n8','','')
n7=TreeNode('n7','','')
n6=TreeNode('n6',n8,n9)
n5=TreeNode('n5','','')
n4=TreeNode('n4','','')
n3=TreeNode('n3',n6,n7)
n2=TreeNode('n2',n4,n5)
n1=TreeNode('n1',n2,n3)
return n1
pass

#前序遍历
def preOrder(self,ref):
if ref=='':
return
print ref.data
self.preOrder(ref.left)
self.preOrder(ref.right)
pass
#中序遍历
def inOrder(self,ref):
if ref=='':
return
self.inOrder(ref.left)
print ref.data
self.inOrder(ref.right)
pass
#后序遍历
def postOrder(self,ref):
if ref=='':
return
self.postOrder(ref.left)
self.postOrder(ref.right)
print ref.data
pass
pass
#----------------------------------------------------------
#实例化树
tree=Tree()
#获取一棵建好的树
t1=tree.get()
#前序遍历
print '前序遍历'
tree.preOrder(t1)
#中序遍历
print '中序遍历'
tree.inOrder(t1)
#后序遍历
print '后序遍历'
tree.postOrder(t1)