Binary
Tree Zigzag Level Order Traversal:
Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to
right, then right to left for the next level and alternate between).
For example:
Given binary tree {3,9,20,#,#,15,7},
3
/ \
9 20
/ \
15 7
return its zigzag level order traversal as:
[
[3],
[20,9],
[15,7]
]
/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode......
阅读全文