Untitled

class Solution {
    private int maxZigZag = 0;
    public int longestZigZag(TreeNode root) {
        dfs(root, true, 0);  // Initialize DFS for the left direction
        return maxZigZag;
    }

      private void dfs(TreeNode node, boolean isLeft, int length) {
        if (node == null) return;

        // Update the global maximum ZigZag length
        maxZigZag = Math.max(maxZigZag, length);

        if (isLeft) {
            // Moving left: Continue with the left child, reset with the right child
            dfs(node.left, false, length + 1);
            dfs(node.right, true, 1);
        } else {
            // Moving right: Continue with the right child, reset with the left child
            dfs(node.right, true, length + 1);
            dfs(node.left, false, 1);
        }
    }

}