549. Binary Tree Longest Consecutive Sequence II

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].

Difficulty:

Medium

Lock:

Prime

Company:

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