摘要：
This question is the same as Binary Tree Treverse in Level Order. Instead of a list, we need ListNode to remeber the result. The tricky part is that w 阅读全文
2017年6月13日
摘要：
Similar to Binary Tree Level Order Travel, just need to add a flag to remeber the order. Change the order to opposite after the level is over. 阅读全文
摘要：
This is very similar to Binary Tree Level Order Traversal. Just reverse the order of the list. ArrayList has API- > add(int index, Element) or Collect 阅读全文
摘要：
This question is very important: 1) Serialization: a. Don't try to do all the things at once. The first step is to get a list of all the tree node. Th 阅读全文
