Binary Tree Longest Consecutive Sequence II is an example of null problems. In this post we will see how we can solve in Javascript.

Problem Description

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:



   / \

  2   3

Output: 2

Explanation: The longest consecutive path is [1, 2] or [2, 1].

Example 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].

If you have different approach in mind or have any suggestion for this implementation feel free to share in the comment below. Thanks!