Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or empty, flip it upside down and turn it into a tree where the original right nodes turned into left leaf nodes. Return the new root.
Example:
Input: [1,2,3,4,5]
1
/ \
2 3
/ \
4 5
Output: return the root of the binary tree [4,5,2,#,#,3,1]
4
/ \
5 2
/ \
3 1
Clarification:
Confused what [4,5,2,#,#,3,1] means? Read
more below on how binary tree is serialized on OJ.
The serialization of a binary tree follows a level order traversal, where '#' signifies a path terminator where no node exists below.
Here's an example:
1
/ \
2 3
/
4
\
5
The above binary tree is serialized as [1,2,3,#,#,4,#,#,5].