class Node(object):
"""元素节点"""
def __init__(self, elem=None, lchild=None, rchild=None):
self.elem = elem
self.lchild = lchild
self.rchild = rchild
class Tree(object):
"""二叉树"""
def __init__(self, root=None):
self.root = root
def add(self,node):
"""添加元素"""
if self.root is None:
self.root = node
else:
li = []
li.append(self.root)
while li:
cur = li.pop(0)
if cur.lchild is None:
cur.lchild = node
return
if cur.rchild is None:
cur.rchild = node
return
li.append(cur.lchild)
li.append(cur.rchild)
def pre_order(self, root):
"""先序遍历"""
if root == None:
return
print(root.elem)
self.pre_order(root.lchild)
self.pre_order(root.rchild)
def mid_order(self, root):
"""中序遍历"""
if root == None:
return
self.mid_order(root.lchild)
print(root.elem)
self.mid_order(root.rchild)
def post_order(self, root):
"""后序遍历"""
if root == None:
return
self.post_order(root.lchild)
self.post_order(root.rchild)
print(root.elem)
if __name__ == '__main__':
tree = Tree()
tree.add(Node("A"))
tree.add(Node("B"))
tree.add(Node("C"))
tree.add(Node("D"))
tree.add(Node("E"))
tree.add(Node("F"))
tree.add(Node("G"))
# tree.pre_order(tree.root)
# tree.mid_order(tree.root)
tree.post_order(tree.root)
