c++ - 如何按某些属性对列表进行排序(只有列表的一个条目)C++

Question

我有一个代表鱼(鳟鱼)许多特征的列表。这些特征之一是生物体的长度 (L)。我对多条鳟鱼进行了编码，因此最终在我的“鳟鱼”列表中有许多具有相同类型属性的鱼。我想按仅一个属性(长度)的降序对列表进行排序，以便列表的第一个对象是最长的鱼，依此类推。我找不到关于 C++ 的有用帖子，我希望有人能帮助我更快地解决这个问题，谢谢!

我曾尝试将 Trout 列表与只有长度的列表压缩在一起，按长度进行子顺序排序，然后仅选择 Trout 条目，但我没有成功。

C++

 class Trout {
         public:
              string species;
              double U_E, V, U_H, U_R; 
              double e_scaled, L;
              double SA, SC; 
              int age, mom_birth, mom_metamorph, mom_maturation;
              double scatter; 
              int ag_step;
              double age_acc, h_acc, Hazard; 
              bool spawn;
              int year_reproduction;
              int day_reproduction;
              int day_birth;
              int year_birth;
            double L_j;
            double L_b ;
            double pA_m_surf, Ub_H, Uj_H, Up_H, g, J_X_Am, E_m_vol, pX_m, L_max;

  Trout(string spc, double aa, double bb, double cc, double dd, double ee, double gg, double hh,
                    int oo,int mb, int mom, int mmat, double ind_variability,  double aging_acceleration,
                    double hazard_rate, double Hazard_f, bool spw, int year_r, int day_r, int day_b, int year_b,
                    double MaxassRate, double matB, double matJ, double matP,
                    double EnRatio, double ingRate, double Edensity, double EingRate, double LengthM,
                    double Lb_sc, double Lj_sc);
              virtual ~Trout(){}
              void printFriendInfo();
      };

      Trout::Trout(string spc, double aa, double bb, double cc, double dd, double ee, double gg, double hh,
                   int oo,int mb, int mom, int mmat, double ind_variability ,  double aging_acceleration,
                   double hazard_rate, double Hazard_f, bool spw, int year_r, int day_r, int day_b, int year_b,
                   double MaxassRate, double matB, double matJ, double matP,
                   double EnRatio, double ingRate, double Edensity, double EingRate, double LengthM,
                   double Lb_sc, double Lj_sc)
      {
        species = spc;
        U_E = aa;  U_H = bb;  U_R = cc;
        e_scaled = dd;

        L = ee;

        SA = gg; SC = hh;
        age = oo;
        mom_birth = mb;  mom_metamorph = mom;  mom_maturation = mmat;
        scatter = ind_variability;
        age_acc = aging_acceleration;
        h_acc = hazard_rate;
        Hazard = Hazard_f;
        spawn = spw;
        year_reproduction = year_r;
        day_reproduction = day_r;
        day_birth = day_b;
        year_birth = year_b;
        pA_m_surf = MaxassRate;
        Ub_H = matB;  Uj_H = matJ;   Up_H = matP;
        g = EnRatio;
        J_X_Am = ingRate;
        E_m_vol = Edensity;
        pX_m = EingRate;
        L_max = LengthM;
        L_b = Lb_sc;
        L_j = Lj_sc;
      };

Answer 1

将 std::sort 与自定义比较器一起使用(在我的示例中使用 lambda)。

std::vector<Trout> trouts;
auto cmp = [](const Trout& lhs, const Trout& rhs){ return lhs.L < rhs.L; };
std::sort(trouts.begin(), trouts.end(), cmp);