class Tree(object):

def __init__(self, ltree=None, rtree=None, data=None):

self.data = data

self.ltree = ltree

self.rtree = rtree

class BTree(object):

def __init__(self, base):

self.base = base

def pre_out(self, tree_base):

'''

前序遍历

'''

if tree_base == None:

return

print(tree_base.data)

self.pre_out(tree_base.ltree)

self.pre_out(tree_base.rtree)

def in_out(self, tree_base):

'''

中序遍历

'''

if tree_base == None:

return

self.in_out(tree_base.ltree)

print(tree_base.data)

self.in_out(tree_base.rtree)

def post_out(self, tree_base):

'''

后序遍历

'''

if tree_base == None:

return

self.in_out(tree_base.rtree)

print(tree_base.data)

self.in_out(tree_base.ltree)

if __name__ == '__main__':

rtree2 = Tree(data=7)

ltree2 = Tree(data=6)

rtree = Tree(ltree=ltree2, rtree=rtree2, data=3)

ltree1 = Tree(data=4)

rtree1 = Tree(data=5)

ltree = Tree(ltree=ltree1, rtree=rtree1, data=2)

base = Tree(ltree=ltree, rtree=rtree, data=1)

btree = BTree(base)

print("----pre_out----")

btree.pre_out(btree.base)

print("----in_out----")

btree.in_out(btree.base)

print("----post_out----")

btree.post_out(btree.base)