摘要： Given a binary tree, return thelevel ordertraversal of its nodes' values. (ie, from left to right, level by level).For example:Given binary tree{3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as:[ [3], [9,20], [15,7] ]/** * Definition for binary tree... 阅读全文