ilp_abs2.cpp

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#include <iostream>
 
#include "qbpp.hpp"
#include "qbpp_abs2.hpp"
 
int main() {
  // Define variables
  auto x1 = 0 <= qbpp::var_int("x1") <= 5;
  auto x2 = 0 <= qbpp::var_int("x2") <= 4;
  auto x3 = 0 <= qbpp::var_int("x3") <= 3;
  auto x4 = 0 <= qbpp::var_int("x4") <= 6;
 
  // Define the objective function
  auto obj = 6 * x1 + 4 * x2 + 3 * x3 + 5 * x4;
 
  // Define the constraints
  auto c1 = x1 + 2 * x2 + 3 * x3 + 4 * x4;
  auto c2 = 3 * x1 + x2 + 2 * x3 + x4;
 
  // Define QUBO expression
  auto f = -obj + 100 * ((0 <= c1 <= 15) + (0 <= c2 <= 10));
 
  auto quad_model = qbpp::QuadModel(f.simplify_as_binary());
 
  // Define the solver
  auto solver = qbpp_abs2::Solver();
 
  // Define the parameters
  auto param = qbpp_abs2::Param();
 
  // Set the time limit
  param.set_time_limit(5);
 
  // Create a default callback function
  qbpp_abs2::Callback callback(quad_model);
 
  // Set the callback function
  param.set(callback);
 
  // Solve the ILP problem
  auto sol = solver(quad_model, param);
 
  // Print the solution
  std::cout << sol << std::endl;
 
  std::cout << "x1 = " << eval(x1, sol) << std::endl;
  std::cout << "x2 = " << eval(x2, sol) << std::endl;
  std::cout << "x3 = " << eval(x3, sol) << std::endl;
  std::cout << "x4 = " << eval(x4, sol) << std::endl;
  std::cout << "c1 = " << eval(c1, sol) << std::endl;
  std::cout << "c2 = " << eval(c2, sol) << std::endl;
  std::cout << "Objective value = " << eval(obj, sol) << std::endl;
}