:github_url: https://github.com/svenevs/exhale-companion


.. _program_listing_file_netoptim_min_cycle_ratio.hpp:

Program Listing for File min_cycle_ratio.hpp
============================================

|exhale_lsh| :ref:`Return to documentation for file <file_netoptim_min_cycle_ratio.hpp>` (``netoptim/min_cycle_ratio.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // -*- coding: utf-8 -*-
   #pragma once
   
   #include "parametric.hpp" // import max_parametric
   #include <algorithm>
   #include <numeric>
   #include <py2cpp/py2cpp.hpp>
   
   template <typename Graph, typename T, typename Fn1, typename Fn2,
       typename Container>
   auto min_cycle_ratio(const Graph& G, T& r0, Fn1&& get_cost, Fn2&& get_time,
       Container&& dist, size_t max_iter = 1000)
   {
       using edge_t = typename Graph::edge_t;
       using cost_T = decltype(get_cost(std::declval<edge_t>()));
       using time_T = decltype(get_time(std::declval<edge_t>()));
   
       auto calc_ratio = [&](const auto& C) -> T
       {
           auto total_cost = cost_T(0);
           auto total_time = time_T(0);
           for (auto&& e : C)
           {
               total_cost += get_cost(e);
               total_time += get_time(e);
           }
           return T(total_cost) / total_time;
       };
   
       auto calc_weight = [&](const T& r, const auto& e) -> T
       { return get_cost(e) - r * get_time(e); };
   
       return max_parametric(G, r0, std::move(calc_weight), std::move(calc_ratio),
           std::forward<Container>(dist), max_iter);
   }