深度优先遍历分为先序遍历,中序遍历,以及后序遍历;而深度遍历的方式又分为递归深度遍历和栈深度遍历。我们现在讨论递归深度遍历的实现方式:
#!/usr/bin/env python
#coding:utf-8
class TreeNode(object):
def __init__(self):
self.data = '#'
self.lchild = None
self.rchild = None
class Tree(TreeNode):
def __init__(self):
self.root = TreeNode()
self.myQueue = []
#Create a tree
def create_tree(self,tree):
data = raw_input('->')
if data == '#':
tree = None
else:
tree.data = data
tree.lchild = TreeNode()
self.create_tree(tree.lchild)
tree.rchild = TreeNode()
self.create_tree(tree.rchild)
def visit(self,tree):
#输入#代表空树
if tree.data is not '#':
print str(tree.data)+'\t'
def pre_order(self,tree):
if tree is not None:
self.visit(tree)
self.pre_order(tree.lchild)
self.pre_order(tree.rchild)
def in_order(self,tree):
if tree is not None:
self.in_order(tree.lchild)
self.visit(tree)
self.in_order(tree.rchild)
def post_order(self,tree):
if tree is not None:
self.post_order(tree.lchild)
self.post_order(tree.rchild)
self.visit(tree)