    // Copyright (C) 2011  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #undef DLIB_MAX_COST_ASSIgNMENT_ABSTRACT_Hh_
    #ifdef DLIB_MAX_COST_ASSIgNMENT_ABSTRACT_Hh_

    #include "../matrix.h"
    #include <vector>

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        template <typename EXP>
        typename EXP::type assignment_cost (
            const matrix_exp<EXP>& cost,
            const std::vector<long>& assignment
        );
        /*!
            requires
                - cost.nr() == cost.nc()
                - for all valid i:
                    - 0 <= assignment[i] < cost.nr()
            ensures
                - Interprets cost as a cost assignment matrix. That is, cost(i,j)
                  represents the cost of assigning i to j.
                - Interprets assignment as a particular set of assignments. That is,
                  i is assigned to assignment[i].
                - returns the cost of the given assignment. That is, returns
                  a number which is:
                    sum over i: cost(i,assignment[i])
        !*/

    // ----------------------------------------------------------------------------------------

        template <typename EXP>
        std::vector<long> max_cost_assignment (
            const matrix_exp<EXP>& cost
        );
        /*!
            requires
                - EXP::type == some integer type (e.g. int)
                  (i.e. cost must contain integers rather than floats or doubles)
                - cost.nr() == cost.nc()
            ensures
                - Finds and returns the solution to the following optimization problem:

                    Maximize: f(A) == assignment_cost(cost, A)
                    Subject to the following constraints:
                        - The elements of A are unique. That is, there aren't any
                          elements of A which are equal.
                        - A.size() == cost.nr()

                - This function implements the O(N^3) version of the Hungarian algorithm
                  where N is the number of rows in the cost matrix.
        !*/

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_MAX_COST_ASSIgNMENT_ABSTRACT_Hh_