Longest Consecutive Path in a Binary Tree

Problem Given a binary tree, return the length of the longest consecutive increasing path. Path requirements: The path must go from parent to child; For every adjacent pair u -> v, v.val = u.val + 1 must hold; The path can start at any node, not necessarily the root. Follow-up: If the path can extend in any direction, meaning it may go from a child to its parent and then to another child, how would you modify the solution? Input Format One line representing the level-order traversal of the binary tree. Empty nodes are represented by null. Output Format Print one integer, the length of the longest consecutive increasing path. Constraints 1 <= number of nodes <= 10^5 -10^9 <= Node.val <= 10^9 Example Input: 1 2 null 3 null 4 null Output: 4 Explanation: The longest path is 1 -> 2 -> 3 -> 4. Example Input 1 2 null 3 null 4 null Output 4