模拟退火算法

前几天计算智能方法的实验作业，简单封装了一下，可以直接调用。

等有空了再完善。

class SimulateAnneal {
  private:
    double eps;
    double inf;
    int itercnt;

  public:
    SimulateAnneal() {
        eps = 1e-12;
        inf = 2e12;
        itercnt = 0;
    }
    double getEps() const { return eps; }
    double getInf() const { return inf; }
    int getItercnt() const { return itercnt; }
    void setEps(const double &_eps) { eps = _eps; }
    void setInf(const double &_inf) { inf = _inf; }

    std::function defaultExponentCooling =
        [](double temp) -> double { return temp * 0.998; };
    std::function defaultLinearCooling =
        [](double temp) -> double { return temp - 0.168; };

    std::function defaultInverseCooling =
        [](double temp) -> double { return temp / (0.0012 * temp + 1); };
    std::function defaultQuickCooling =
        [&](double temp) -> double { return temp / (getItercnt() + 1); };
    std::function defaultLogarithmicCooling =
        [&](double temp) -> double { return 3000.0 / (std::log1p(getItercnt()) + 1); };

    template 
    std::pair>
    solve(std::vector &initial,
          const std::function &)> &calc,
          const std::function &better,
          const std::function(std::vector &, double)> &change,
          const std::function &CoolingSchedule,
          double temperature) {
        std::vector current = initial;
        std::vector ret = initial;
        T ans = calc(current);
        itercnt = 0;
        std::uniform_real_distribution P(0, 1.0);
        std::random_device rd;
        std::default_random_engine engine{rd()};
        while (temperature > eps) {
            std::vector now = change(current, temperature);
            T value = calc(now);
            double delta = -fabs(value - ans);
            if (better(value, ans)) {
                current = now;
                ret = now;
                ans = value;
            } else if (exp(delta / temperature) > P(engine)) {
                current = now;
            }
            temperature = CoolingSchedule(temperature);
            itercnt++;
        }
        return {ans, ret};
    }
};