pyepo.model.utils
=================

.. py:module:: pyepo.model.utils

.. autoapi-nested-parse::

   Problem-level helpers for optimization model construction.



Classes
-------

.. autoapisummary::

   pyepo.model.utils.unionFind


Functions
---------

.. autoapisummary::

   pyepo.model.utils.getTspTour


Module Contents
---------------

.. py:class:: unionFind(n: int)

   Union-Find data structure for cycle detection in graphs


   .. py:attribute:: parent


   .. py:method:: find(i: int) -> int


   .. py:method:: union(i: int, j: int) -> bool


.. py:function:: getTspTour(edge_list: list[tuple[int, int]], num_nodes: int, sol: numpy.ndarray | torch.Tensor | list, threshold: float = _EDGE_ACTIVE_TOL) -> list[int]

   Reconstruct a TSP tour from an undirected edge-selection vector.

   :param edge_list: undirected edges of the model, ordered to match ``sol``
   :param num_nodes: number of nodes in the TSP instance
   :param sol: solution values aligned with ``edge_list``; an edge is
               considered active when its value exceeds ``threshold``
   :param threshold: activation threshold for an edge

   :returns: node sequence of the tour, starting and ending at node 0
   :rtype: list

   :raises ValueError: if the solution does not form a single Hamiltonian tour
       closed back to node 0 (skips nodes, contains disconnected subtours,
       or the last visited node is not adjacent to 0).