IMPLEMENTED_LOCAL_TESTEDTSP bounds

ALGORITHM ARTICLE

One-tree lower bound

Problem. Certified lower bound for symmetric TSP.

Core idea. Combine an MST excluding the depot with its two cheapest incident edges.

Procedure

  1. Build the non-depot MST.
  2. Select two cheapest depot edges.
  3. Add both costs.

Certificate. Every tour induces such a spanning structure.

Data structures and API

from optfin_orlab.tsp import TSP

solver = TSP()
result = solver.lower_bound(...)

Complexity. O(n²) in the dense implementation

Limits. It is not generally a feasible tour.

OPTFIN AUDIT CHECKS

What has to reconcile before this method is trusted.

  • DefinitionProblem, objective, inputs and output are explicit.
  • Data structureThe public API and canonical source path are identified.
  • CorrectnessEvery tour induces such a spanning structure.
  • ComplexityO(n²) in the dense implementation
  • Operational limitIt is not generally a feasible tour.
  • ReproductionSource, executable test and evidence route remain linked.

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