/* Copyright 2025, Gurobi Optimization, LLC *//* This example reads an LP model from a file and solves it.   If the model can be solved, then it finds the smallest positive variable,   sets its upper bound to zero, and resolves the model two ways:   first with an advanced start, then without an advanced start   (i.e. 'from scratch'). */importcom.gurobi.gurobi.*;publicclassLpmod{publicstaticvoidmain(String[]args){if(args.length<1){System.out.println("Usage: java Lpmod filename");System.exit(1);}try{// Read model and determine whether it is an LPGRBEnvenv=newGRBEnv();GRBModelmodel=newGRBModel(env,args[0]);if(model.get(GRB.IntAttr.IsMIP)!=0){System.out.println("The model is not a linear program");System.exit(1);}model.optimize();intstatus=model.get(GRB.IntAttr.Status);if(status==GRB.Status.INF_OR_UNBD||status==GRB.Status.INFEASIBLE||status==GRB.Status.UNBOUNDED){System.out.println("The model cannot be solved because it is "+"infeasible or unbounded");System.exit(1);}if(status!=GRB.Status.OPTIMAL){System.out.println("Optimization was stopped with status "+status);System.exit(0);}// Find the smallest variable valuedoubleminVal=GRB.INFINITY;GRBVarminVar=null;for(GRBVarv:model.getVars()){doublesol=v.get(GRB.DoubleAttr.X);if((sol>0.0001)&&(sol<minVal)&&(v.get(GRB.DoubleAttr.LB)==0.0)){minVal=sol;minVar=v;}}System.out.println("\n*** Setting "+minVar.get(GRB.StringAttr.VarName)+" from "+minVal+" to zero ***\n");minVar.set(GRB.DoubleAttr.UB,0.0);// Solve from this starting pointmodel.optimize();// Save iteration & time infodoublewarmCount=model.get(GRB.DoubleAttr.IterCount);doublewarmTime=model.get(GRB.DoubleAttr.Runtime);// Reset the model and resolveSystem.out.println("\n*** Resetting and solving "+"without an advanced start ***\n");model.reset();model.optimize();doublecoldCount=model.get(GRB.DoubleAttr.IterCount);doublecoldTime=model.get(GRB.DoubleAttr.Runtime);System.out.println("\n*** Warm start: "+warmCount+" iterations, "+warmTime+" seconds");System.out.println("*** Cold start: "+coldCount+" iterations, "+coldTime+" seconds");// Dispose of model and environmentmodel.dispose();env.dispose();}catch(GRBExceptione){System.out.println("Error code: "+e.getErrorCode()+". "+e.getMessage());}}}