114. 二叉树展开为链表
class Solution:
def flatten(self, root):
"""
:type root: TreeNode
:rtype: void Do not return anything, modify root in-place instead.
"""
if root == None:
return
self.flatten(root.left)
self.flatten(root.right)
p = root
if p.left == None:
return
p = p.left
while p.right:
p = p.right
p.right = root.right
root.right = root.left
root.left = None