Binary Tree Longest Consecutive Sequence II
CodingPhone Screen, OnsiteSoftware EngineerReported Feb, 2026
Examples
Example 1:
Input: root = [1,2,3]
Output: 2
Explanation:
Example 2:
Input: root = [2,1,3]
Output: 3
Explanation:
Example 1:
Input: root = [1,2,3]
Output: 2
Explanation:
Example 2:
Input: root = [2,1,3]
Output: 3
Explanation:
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 adjacent nodes differ by one. This path can be either increasing or decreasing.
For example, [1,2,3,4] and [4,3,2,1] are both valid consecutive paths, but [1,2,4,3] is not.
The path can also follow the child-parent-child direction and does not need to stay in a single parent-to-child direction.
The longest consecutive path is [1,2] or [2,1].
The longest consecutive path is [1,2,3] or [3,2,1].
1 <= Number of nodes <= 3 * 10^4-3 * 10^4 <= Node.val <= 3 * 10^4