order.hpp

#ifndef ORDER_HPP_
#define ORDER_HPP_

#include "types.hpp"

enum order_heur {
    O_WEIGHTED_MIN_FILL,
    O_MIN_FILL,
    O_MIN_INDUCED_WIDTH,
    O_MIN_DEGREE,
    O_RANDOM
};

enum tie_heur {
    T_UNIQUENESS,
    T_RANDOM
};

#include <limits>   // std::numeric_limits

template <typename T>
struct compare_vec {
    compare_vec(std::vector<T> const &vec) : vec(vec) {};
    bool operator()(size_t const &x, size_t const &y) {
        if constexpr (std::is_integral_v<T>) {
            return vec[x] < vec[y];
        } else if (std::is_floating_point_v<T>) {
            return vec[x] < vec[y] - std::numeric_limits<weight>::epsilon();
        }
    }
    std::vector<T> vec;
};

std::vector<size_t> greedy_order(std::vector<std::vector<weight>> const &adj, int order_heur = O_WEIGHTED_MIN_FILL, int tie_heur = T_UNIQUENESS);

size_t induced_width(std::vector<std::vector<weight>> const &adj, std::vector<size_t> const &order);

std::vector<size_t> read_pseudotree_order(const char *filename, std::vector<size_t> const &domains);

void export_order(std::vector<size_t> const &order, std::vector<size_t> const &domains, const char *output);

#endif