Solve

Step 16: Create an instance of IloCP

Add the following code after the comment //Create an instance of IloCP

    IloCP cp(model);

You now use the member function IloCP::solve, which solves the problem contained in the model by using constructive search and constraint propagation. The search for an optimal solution in this problem could potentiality take a long time, so you place a fail limit on the solve process. The search will stop when the fail limit is reached, even if optimality of the current best solution is not guaranteed.

Step 17: Search for a solution

Add the following code after the comment //Search for a solution

    cp.setParameter(IloCP::FailLimit, 30000);
    if (cp.solve()) {

The member function IloCP::solve returns a Boolean value of type IloBool. If a solution is found, the value IloTrue is returned.

After a solution has been found, you can use the member functions IloCP::getObjValue and IloCP::domain to examine the solution. The stream IloAlgorithm::out is the communication stream for general output. The code for displaying the solution has been provided for you:

      cp.out() << "Solution with objective " << cp.getObjValue() << ":" << std::endl;
      for (i=0; i<allTasks.getSize(); ++i) {
        cp.out() << cp.domain(allTasks[i]) << std::endl;
      }

Step 18: Compile and run the program

Compile and run the program. You should get the following results:

Solution with objective 13852:
H0-masonry  [1: 1 -- 35 --> 36]
H0-carpentry[1: 36 -- 15 --> 51]
H0-plumbing [1: 36 -- 40 --> 76]
H0-ceiling  [1: 76 -- 15 --> 91]
H0-roofing  [1: 51 -- 5 --> 56]
H0-painting [1: 91 -- 10 --> 101]
H0-windows  [1: 101 -- 5 --> 106]
H0-facade   [1: 97 -- 10 --> 107]
H0-garden   [1: 107 -- 5 --> 112]
H0-moving   [1: 112 -- 5 --> 117]
H1-masonry  [1: 138 -- 35 --> 173]
H1-carpentry[1: 192 -- 15 --> 207]
H1-plumbing [1: 197 -- 40 --> 237]
H1-ceiling  [1: 237 -- 15 --> 252]
H1-roofing  [1: 207 -- 5 --> 212]
H1-painting [1: 252 -- 10 --> 262]
H1-windows  [1: 262 -- 5 --> 267]
H1-facade   [1: 252 -- 10 --> 262]
H1-garden   [1: 262 -- 5 --> 267]
H1-moving   [1: 267 -- 5 --> 272]
H2-masonry  [1: 216 -- 35 --> 251]
H2-carpentry[1: 268 -- 15 --> 283]
H2-plumbing [1: 273 -- 40 --> 313]
H2-ceiling  [1: 313 -- 15 --> 328]
H2-roofing  [1: 283 -- 5 --> 288]
H2-painting [1: 328 -- 10 --> 338]
H2-windows  [1: 338 -- 5 --> 343]
H2-facade   [1: 333 -- 10 --> 343]
H2-garden   [1: 328 -- 5 --> 333]
H2-moving   [1: 343 -- 5 --> 348]
H3-masonry  [1: 59 -- 35 --> 94]
H3-carpentry[1: 115 -- 15 --> 130]
H3-plumbing [1: 120 -- 40 --> 160]
H3-ceiling  [1: 160 -- 15 --> 175]
H3-roofing  [1: 130 -- 5 --> 135]
H3-painting [1: 175 -- 10 --> 185]
H3-windows  [1: 185 -- 5 --> 190]
H3-facade   [1: 180 -- 10 --> 190]
H3-garden   [1: 175 -- 5 --> 180]
H3-moving   [1: 190 -- 5 --> 195]
H4-masonry  [1: 291 -- 35 --> 326]
H4-carpentry[1: 345 -- 15 --> 360]
H4-plumbing [1: 350 -- 40 --> 390]
H4-ceiling  [1: 390 -- 15 --> 405]
H4-roofing  [1: 360 -- 5 --> 365]
H4-painting [1: 405 -- 10 --> 415]
H4-windows  [1: 415 -- 5 --> 420]
H4-facade   [1: 390 -- 10 --> 400]
H4-garden   [1: 400 -- 5 --> 405]
H4-moving   [1: 420 -- 5 --> 425]

The complete program can be viewed in the <Install_dir>/cpoptimizer/examples/src/cpp/sched_sequence.cpp file.