0549. Binary Tree Longest Consecutive Sequence II

https://leetcode.com/problems/binary-tree-longest-consecutive-sequence-ii

Description

Given the root of a binary tree, return the length of the longest consecutive path in the tree.

A consecutive path is a path where the values of the consecutive nodes in the path differ by one. 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:** root = [1,2,3]
**Output:** 2
**Explanation:** The longest consecutive path is [1, 2] or [2, 1].

Example 2:

**Input:** root = [2,1,3]
**Output:** 3
**Explanation:** The longest consecutive path is [1, 2, 3] or [3, 2, 1].

Constraints:

• The number of nodes in the tree is in the range [1, 3 * 104].

• -3 * 104 <= Node.val <= 3 * 104

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