主要是：前序遍历、中序遍历、后序遍历、层级遍历、非递归前序遍历、非递归中序遍历、非递归后序遍历
class TreeNode(object):
def __init__(self, data=None, left=None, right=None):
self.data = data
self.left = left
self.right = right
class Tree(object):
def __init__(self, root=None):
self.root = None
def makeTree(self, data, left, right):
self.root = TreeNode(data, left, right)
def is_empty(self):
"""是否为空 """
if self.root is None:
return True
return False
def preOrder(self, r):
"""前序遍历 """
if not r.is_empty():
print r.root.data
if r.root.left is not None:
r.preOrder(r.root.left)
if r.root.right is not None:
r.preOrder(r.root.right)
def inOrder(self, r):
"""中序遍历 """
if not r.is_empty():
if r.root.left is not None:
r.preOrder(r.root.left)
print r.root.data
if r.root.right is not None:
r.preOrder(r.root.right)
def postOrder(self, r):
"""后续遍历 """
if not r.is_empty():
if r.root.left is not None:
r.preOrder(r.root.left)
print r.root.data
if r.root.right is not None:
r.preOrder(r.root.right)
def levelOrder(self, r):
"""层级遍历 """
if not r.is_empty():
s = [r]
while len(s) > 0:
temp = s.pop(0) # 先弹出最先append到的点
if temp and temp.root is not None:
print temp.root.data
if temp.root.left is not None:
s.append(temp.root.left)
if self.root.right is not None:
s.append(temp.root.right)
def preOrder1(self, r):
"""非递归 前序遍历 """
stack = []
current = r
while len(stack) > 0 or (current and not current.is_empty()):
while current and not current.is_empty():
print current.root.data
stack.append(current)
current = current.root.left
if len(stack) > 0:
current = stack.pop()
current = current.root.right
def inOrder1(self, r):
"""非递归 中序遍历 """
stack = []
current = r
while len(stack) > 0 or (current and not current.is_empty()):
while current and not current.is_empty():
stack.append(current)
current = current.root.left
if len(stack) > 0:
current = stack.pop()
print current.root.data
current = current.root.right
def postOrder1(self, r):
"""非递归 后续遍历 """
stack = []
current = r
pre = None
while len(stack) > 0 or (current and not current.is_empty()):
if current and not current.is_empty():
stack.append(current)
current = current.root.left
elif stack[-1].root.right != pre:
&n