/******************************************************** Xpress-BCL C# Example Problems ============================== file xbcontr1.cs ```````````````` Contract allocation example. Combining BCL problem input with problem solving in Xpress-Optimizer. (c) 2008 Fair Isaac Corporation authors: S.Heipcke, D.Brett. ********************************************************/ using System; using System.Text; using System.IO; using BCL; namespace Examples { public class TestContract { const int District = 6; /* Number of districts */ const int Contract = 10; /* Number of contracts */ /**** DATA ****/ int[] OUTPUT = {50, 40, 10, 20, 70, 50}; /* Max. output per district */ int[] COST = {50, 20, 25, 30, 45, 40}; /* Cost per district */ int[] VOLUME = {20, 10, 30, 15, 20, 30, 10, 50, 10, 20}; /* Volume of contracts */ /***********************************************************************/ public static void Main() { XPRB.init(); int d,c; XPRBprob p = new XPRBprob("Contract"); /* Initialize a new problem in BCL */ XPRBexpr l1,l2,lobj; XPRBvar[,] x = new XPRBvar[District,Contract]; /* Variables indicating whether a project is chosen */ XPRBvar[,] y = new XPRBvar[District,Contract]; /* Quantities allocated to contractors */ TestContract TestInstance = new TestContract(); /**** VARIABLES ****/ for(d=0;d<District;d++) for(c=0;c<Contract;c++) x[d,c]=p.newVar("x_d" +="c" y[d,c]=p.newVar("q_d" lobj=new for(d=0;d<District;d++) Set the objective function CONSTRAINTS l1=new l2=new>= TestInstance.VOLUME[c]);  /* "Size": cover the required volume */
                p.newCtr("Min", l2 >= 2 ); 	 /* "Min": at least 2 districts per contract */
            }

            for(d=0;d<District;d++) Do not exceed max. output of any district l1=new for(c=0;c<Contract;c++) +=y[d,c]; <=TestInstance.OUTPUT[d]); for(d=0;d<District;d++) If a contract is allocated to then at least unit it Output the matrix in MPS format Choose sense optimization Solve MIP-problem if((p.getMIPStat()==BCLconstant.XPRB_MIP_SOLUTION) (p.getMIPStat()==BCLconstant.XPRB_MIP_OPTIMAL)) Test whether an integer sol. was found>0)
                        System.Console.Write(y[d, c].getName() + ":" + y[d, c].getSol() + ", ");
                    System.Console.WriteLine();
                }
            } 
            return;
        } 
    }
}