The Munkres module provides an O(n^3) implementation of the Munkres
algorithm (also called the Hungarian algorithm or the Kuhn-Munkres
algorithm). The algorithm models an assignment problem as an NxM cost
matrix, where each element represents the cost of assigning the i'th
worker to the j'th job, and it figures out the least-cost solution,
choosing a single item from each row and column in the matrix, such
that no row and no column are used more than once.
This particular implementation is based on