Workforce1.java.
/ *版权所有2021，Gurobi优狗万app足彩化，LLC * / / *分配工人转移;每个工人都可能或可能无法在特定日期上使用。如果问题无法解决，请使用IIS查找一组冲突的约束。请注意，除了通过IIS报告的内容外，可能存在额外的冲突。* /进口gurobi。*;公共类Workforce1 {公共静态void main（String [] args）{try {//示例数据//工作者和工人字符串shifts [] = new string [] {mon1“，”tue2“，”wed3“，“星期四”，“星期五”，“SAT6”，“Sun7”，“Mon8”，“Tue9”，“Wed10”，“星期四”，“星期五”，“星期五”，“SAT13”，“Sun14”};字符串工人[] =新字符串[] {“amy”，“鲍勃”，“凯茜”，“丹”，“ed”，“fred”，“gu”};int nshifts = shifts.length;int nworkers = workers.Length; // Number of workers required for each shift double shiftRequirements[] = new double[] { 3, 2, 4, 4, 5, 6, 5, 2, 2, 3, 4, 6, 7, 5 }; // Amount each worker is paid to work one shift double pay[] = new double[] { 10, 12, 10, 8, 8, 9, 11 }; // Worker availability: 0 if the worker is unavailable for a shift double availability[][] = new double[][] { { 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1 }, { 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0 }, { 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1 }, { 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1 }, { 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1 }, { 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1 }, { 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 } }; // Model GRBEnv env = new GRBEnv(); GRBModel model = new GRBModel(env); model.set(GRB.StringAttr.ModelName, "assignment"); // Assignment variables: x[w][s] == 1 if worker w is assigned // to shift s. Since an assignment model always produces integer // solutions, we use continuous variables and solve as an LP. GRBVar[][] x = new GRBVar[nWorkers][nShifts]; for (int w = 0; w < nWorkers; ++w) { for (int s = 0; s < nShifts; ++s) { x[w][s] = model.addVar(0, availability[w][s], pay[w], GRB.CONTINUOUS, Workers[w] + "." + Shifts[s]); } } // The objective is to minimize the total pay costs model.set(GRB.IntAttr.ModelSense, GRB.MINIMIZE); // Constraint: assign exactly shiftRequirements[s] workers // to each shift s for (int s = 0; s < nShifts; ++s) { GRBLinExpr lhs = new GRBLinExpr(); for (int w = 0; w < nWorkers; ++w) { lhs.addTerm(1.0, x[w][s]); } model.addConstr(lhs, GRB.EQUAL, shiftRequirements[s], Shifts[s]); } // Optimize model.optimize(); int status = model.get(GRB.IntAttr.Status); if (status == GRB.Status.UNBOUNDED) { System.out.println("The model cannot be solved " + "because it is unbounded"); return; } if (status == GRB.Status.OPTIMAL) { System.out.println("The optimal objective is " + model.get(GRB.DoubleAttr.ObjVal)); return; } if (status != GRB.Status.INF_OR_UNBD && status != GRB.Status.INFEASIBLE ){ System.out.println("Optimization was stopped with status " + status); return; } // Compute IIS System.out.println("The model is infeasible; computing IIS"); model.computeIIS(); System.out.println("\nThe following constraint(s) " + "cannot be satisfied:"); for (GRBConstr c : model.getConstrs()) { if (c.get(GRB.IntAttr.IISConstr) == 1) { System.out.println(c.get(GRB.StringAttr.ConstrName)); } } // Dispose of model and environment model.dispose(); env.dispose(); } catch (GRBException e) { System.out.println("Error code: " + e.getErrorCode() + ". " + e.getMessage()); } } }
