from collections import deque
class TreeNode(object):
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Tree(object):
"""
非二叉搜索树，建树的时候values中的顺序需要注意
之后有时间会改成二叉搜索树
"""
def __init__(self):
self.root = None
def construct_tree(self, values=None):
# 结点值不存在的话，values中用None表示
if not values:
return None
self.root = TreeNode(values[0])
queue = deque([self.root])
leng = len(values)
nums = 1
while nums < leng:
node = queue.popleft()
if node:
node.left = TreeNode(values[nums]) if values[nums] else None
queue.append(node.left)
if nums + 1 < leng:
node.right = TreeNode(values[nums + 1]) if values[nums + 1] else None
queue.append(node.right)
nums += 1
nums += 1
def bfs(self):
ret = []
queue = deque([self.root])
while queue:
node = queue.popleft()
if node:
ret.append(node.val)
queue.append(node.left)
queue.append(node.right)
return ret
class Solution(object):
@staticmethod
def convert(tree):
"""结点转换"""
if not tree:
return None
p_last = Solution.convert_nodes(tree, None)
while p_last and p_last.left: # 获取链表头结点
p_last = p_last.left
return p_last
@staticmethod
def convert_nodes(tree, last):
if not tree:
return None
if tree.left:
last = Solution.convert_nodes(tree.left, last)
if last:
last.right = tree
tree.left = last
last = tree
if tree.right:
last = Solution.convert_nodes(tree.right, last)
return last
@staticmethod
def print_nodes(tree):
# 正序链表打印
ret = []
while tree:
tmp = []
tmp.append(tree.left.val if tree.left else None)
tmp.append(tree.val)
tmp.append(tree.right.val if tree.right else None)
ret.append(tmp)
tree = tree.right
print ret
if __name__ == '__main__':
r = Tree()
# r.construct_tree([2, 1])
# r.construct_tree([2, None, 3])
# r.construct_tree([2, 1, 3])
# r.construct_tree([])
r.construct_tree([5, 3, 6, 2, 4, None, 7, 1])
t = Solution.convert(r.root)
Solution.print_nodes(t)
