Class Solution
java.lang.Object
g1301_1400.s1372_longest_zigzag_path_in_a_binary_tree.Solution
1372 - Longest ZigZag Path in a Binary Tree\.
Medium
You are given the `root` of a binary tree.
A ZigZag path for a binary tree is defined as follow:
* Choose **any** node in the binary tree and a direction (right or left).
* If the current direction is right, move to the right child of the current node; otherwise, move to the left child.
* Change the direction from right to left or from left to right.
* Repeat the second and third steps until you can't move in the tree.
Zigzag length is defined as the number of nodes visited - 1. (A single node has a length of 0).
Return _the longest **ZigZag** path contained in that tree_.
**Example 1:**

**Input:** root = [1,null,1,1,1,null,null,1,1,null,1,null,null,null,1,null,1]
**Output:** 3
**Explanation:** Longest ZigZag path in blue nodes (right -> left -> right).
**Example 2:**

**Input:** root = [1,1,1,null,1,null,null,1,1,null,1]
**Output:** 4
**Explanation:** Longest ZigZag path in blue nodes (left -> right -> left -> right).
**Example 3:**
**Input:** root = [1]
**Output:** 0
**Constraints:**
* The number of nodes in the tree is in the range
[1, 5 * 104].
* `1 <= Node.val <= 100`-
Constructor Summary
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Solution
public Solution()
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Method Details
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longestZigZag
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