/* -*- C++ -*- * * This file is a part of LEMON, a generic C++ optimization library * * Copyright (C) 2003-2008 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport * (Egervary Research Group on Combinatorial Optimization, EGRES). * * Permission to use, modify and distribute this software is granted * provided that this copyright notice appears in all copies. For * precise terms see the accompanying LICENSE file. * * This software is provided "AS IS" with no warranty of any kind, * express or implied, and with no claim as to its suitability for any * purpose. * */ #include <lemon/lp.h> #include <iostream> using namespace lemon; int main() { //The following example is taken from the documentation of the GLPK library. //See it in the GLPK reference manual and among the GLPK sample files (sample.c) //A default solver is taken Lp lp; typedef Lp::Row Row; typedef Lp::Col Col; std::cout<<"A program demonstrating the LEMON LP solver interface"<<std::endl; std::cout<<"Solver used: "<<default_solver_name<<std::endl; //This will be a maximization lp.max(); //We add coloumns (variables) to our problem Col x1 = lp.addCol(); Col x2 = lp.addCol(); Col x3 = lp.addCol(); //Constraints lp.addRow(x1+x2+x3 <=100); lp.addRow(10*x1+4*x2+5*x3<=600); lp.addRow(2*x1+2*x2+6*x3<=300); //Nonnegativity of the variables lp.colLowerBound(x1, 0); lp.colLowerBound(x2, 0); lp.colLowerBound(x3, 0); //Objective function lp.obj(10*x1+6*x2+4*x3); //Call the routine of the underlying LP solver lp.solve(); //Print results if (lp.primalStatus()==LpSolverBase::OPTIMAL){ std::cout<<"Optimal solution found!"<<std::endl; printf("optimum value = %g; x1 = %g; x2 = %g; x3 = %g\n", lp.primalValue(), lp.primal(x1), lp.primal(x2), lp.primal(x3)); } else{ std::cout<<"Optimal solution not found!"<<std::endl; } //End of LEMON style code //Here comes the same problem written in C using GLPK API routines // LPX *lp; // int ia[1+1000], ja[1+1000]; // double ar[1+1000], Z, x1, x2, x3; // s1: lp = lpx_create_prob(); // s2: lpx_set_prob_name(lp, "sample"); // s3: lpx_set_obj_dir(lp, LPX_MAX); // s4: lpx_add_rows(lp, 3); // s5: lpx_set_row_name(lp, 1, "p"); // s6: lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0); // s7: lpx_set_row_name(lp, 2, "q"); // s8: lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0); // s9: lpx_set_row_name(lp, 3, "r"); // s10: lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0); // s11: lpx_add_cols(lp, 3); // s12: lpx_set_col_name(lp, 1, "x1"); // s13: lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0); // s14: lpx_set_obj_coef(lp, 1, 10.0); // s15: lpx_set_col_name(lp, 2, "x2"); // s16: lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0); // s17: lpx_set_obj_coef(lp, 2, 6.0); // s18: lpx_set_col_name(lp, 3, "x3"); // s19: lpx_set_col_bnds(lp, 3, LPX_LO, 0.0, 0.0); // s20: lpx_set_obj_coef(lp, 3, 4.0); // s21: ia[1] = 1, ja[1] = 1, ar[1] = 1.0; /* a[1,1] = 1 */ // s22: ia[2] = 1, ja[2] = 2, ar[2] = 1.0; /* a[1,2] = 1 */ // s23: ia[3] = 1, ja[3] = 3, ar[3] = 1.0; /* a[1,3] = 1 */ // s24: ia[4] = 2, ja[4] = 1, ar[4] = 10.0; /* a[2,1] = 10 */ // s25: ia[5] = 3, ja[5] = 1, ar[5] = 2.0; /* a[3,1] = 2 */ // s26: ia[6] = 2, ja[6] = 2, ar[6] = 4.0; /* a[2,2] = 4 */ // s27: ia[7] = 3, ja[7] = 2, ar[7] = 2.0; /* a[3,2] = 2 */ // s28: ia[8] = 2, ja[8] = 3, ar[8] = 5.0; /* a[2,3] = 5 */ // s29: ia[9] = 3, ja[9] = 3, ar[9] = 6.0; /* a[3,3] = 6 */ // s30: lpx_load_matrix(lp, 9, ia, ja, ar); // s31: lpx_simplex(lp); // s32: Z = lpx_get_obj_val(lp); // s33: x1 = lpx_get_col_prim(lp, 1); // s34: x2 = lpx_get_col_prim(lp, 2); // s35: x3 = lpx_get_col_prim(lp, 3); // s36: printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3); // s37: lpx_delete_prob(lp); // return 0; return 0; }
#include <lemon/lp.h>#include <iostream> 1.5.9