带约束的元组允许火车旅行答案

【问题标题】：tuple with constraint permitted train travel带约束的元组允许火车旅行
【发布时间】：2021-12-30 15:11:44
【问题描述】：

我有一个卡住的问题，我想写一个元组约束，条件是

P_ij ={k in L |k 允许执行从 I 到 j 的行程}

其中k是机车符号，L是可用机车的集合，我写了，我感觉不对，因为元组只有起点和目的地而没有提到k，但数据只需要k，所以我应该如何解决它。注意数据没有变化

      {string} Node=...;
     {string} Locomotive=...;

      tuple P{
      string i;
      string j;
      string Locomotive;
      };

     {P} Pij =...;

     {string} IJ= {k |k in Locomotive} inter {<i,j,k>| k in Pij}; 

      and My Data
        
       Node={"S","V","K","G","V1","V2","V3","V4"}
       Locomotive={"L1","L2","L3","L4"}
          Pij
              i   j    Pij    
              S   V1   L1   
              V   V2   L2
              K   V3   L3
              G   V4   L4

【问题讨论】：

标签： algorithm constraints scheduled-tasks cplex opl

【解决方案1】：

.mod

{string} Node=...;
{string} Locomotive=...;

      tuple P{
      string i;
      string j;
      string Locomotivet;
      };

{P} Pij =...;
     
{string} L[i in Node][j in Node]={l | l in Locomotive : <i,j,l> in Pij};

execute
{
  writeln(L["G"]["V4"]);
}

.dat

Node={"S","V","K","G","V1","V2","V3","V4"};
       Locomotive={"L1","L2","L3","L4"};
          Pij=
              {   
              <S,   V1,   L1>,   
              <V,   V2,   L2>,
              <K,   V3,   L3>,
              <G,   V4,   L4>};

给予

{"L4"}

【讨论】：