Heuristic Objective
(heuristic/objective.hpp)

• View this file on GitHub
• Last update: 2026-08-12 20:17:35+09:00
• Include: #include "heuristic/objective.hpp"

Overview

Shared minimization and maximization vocabulary for heuristic search policies. Most users only need to pass an Objective when constructing or calling a search tool:

#include "heuristic/hill_climbing.hpp"

using m1une::heuristic::Objective;

m1une::heuristic::HillClimbing climbing(Objective::minimize);

The default objective in every heuristic header is Objective::maximize.

Interface

Interface	Description	Complexity
enum class Objective { minimize, maximize };	Selects whether smaller or larger scores rank first.	$O(1)$
bool better_score(const Score& first, const Score& second, Objective objective)	Returns whether first is strictly better than second. Score must support <.	$O(1)$ plus one or two score comparisons

AnnealingObjective and HillClimbingObjective are aliases of Objective, so one objective value can be reused across local-search policies.

better_score(first, second, objective) is mainly a helper for implementing other heuristic algorithms. It is strict: equal scores return false in both directions.

Required by

• Heuristic Search (heuristic/all.hpp)
• Beam Search (heuristic/beam_search.hpp)
• Hill Climbing (heuristic/hill_climbing.hpp)
• Simulated Annealing (heuristic/simulated_annealing.hpp)

Verified with

• verify/heuristic/beam_search.test.cpp
• verify/heuristic/hill_climbing.test.cpp
• verify/heuristic/simulated_annealing.test.cpp

Code

#ifndef M1UNE_HEURISTIC_OBJECTIVE_HPP
#define M1UNE_HEURISTIC_OBJECTIVE_HPP 1

namespace m1une {
namespace heuristic {

enum class Objective {
    minimize,
    maximize,
};

template <class Score>
bool better_score(const Score& first, const Score& second,
                  Objective objective) {
    if (objective == Objective::maximize) return second < first;
    return first < second;
}

}  // namespace heuristic
}  // namespace m1une

#endif  // M1UNE_HEURISTIC_OBJECTIVE_HPP

#line 1 "heuristic/objective.hpp"



namespace m1une {
namespace heuristic {

enum class Objective {
    minimize,
    maximize,
};

template <class Score>
bool better_score(const Score& first, const Score& second,
                  Objective objective) {
    if (objective == Objective::maximize) return second < first;
    return first < second;
}

}  // namespace heuristic
}  // namespace m1une

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