Linear-time algorithm for the tree case
Determine whether the restricted inverse optimal value problem on shortest paths under the weighted l∞ norm on trees admits an O(n)-time algorithm, improving on the two O(n log n)-time algorithms developed in the paper.
References
Second, both of our algorithms run in O(n log n) time. Whether a linear-time algorithm exists remains open.
— The Restricted Inverse Optimal Value Problem on Shortest Path under $l_\infty$ Norm on Trees
(2610.23710 - Zhang et al., 16 Oct 2026) in Conclusion, p. 35