【算法与数据结构4】树结构进阶

深度优先遍历

前序：DBACFEG

def preorder(x):
	if x is None:
		return
	print(x.label)
	print(x.left)
	print(x.right)

中序：ABCDEFG

def inorder(x):
	if x is None:
		return
	inorder(x.left)
	print(x.label)
	inorder(x.right)

后序：ACBEDFG

def postorder(x):
		if x is None:
		return
	postorder(x.left)
	postorder(x.right)
	print(x.label)

![在这里插入图片描述](https://img-blog.csdnimg.cn/cdaa7072d7f04a2ea4a2052ff8a5b135.png

二叉树层序遍历

def levelorder(x):
	for i in range(h,height):
		 visit_level(x,i)

def visit_level(x,i):
	if x is None:
		return
	if i == 0:
		print(x.label)
	else:
		visit_level(x.left,i-1)
		visit_level(x.right,i-1)

多维数据处理