Binary Tree Longest Consecutive Sequence II

Similar Problems:

- Leetcode: Binary Tree Longest Consecutive Sequence
- CheatSheet: Leetcode For Code Interview
- Tag: #binarytree, #treetraversal, #inspiring

Given a binary tree, you need to find the length of Longest Consecutive Path in Binary Tree.

Especially, this path can be either increasing or decreasing. For example, [1,2,3,4] and [4,3,2,1] are both considered valid, but the path [1,2,4,3] is not valid. On the other hand, the path can be in the child-Parent-child order, where not necessarily be parent-child order.

Example 1:

Input: 1 / \ 2 3 Output: 2 Explanation: The longest consecutive path is [1, 2] or [2, 1].

Example 2:

Input: 2 / \ 1 3 Output: 3 Explanation: The longest consecutive path is [1, 2, 3] or [3, 2, 1].

Note: All the values of tree nodes are in the range of [-1e7, 1e7].

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

- Solution:

**General Thinkings:**

**Key Observations:**

**Walk Through Testdata**

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