/* Copyright 2025, Gurobi Optimization, LLC This example formulates and solves the following simple model with PWL constraints:  maximize        sum c[j] * x[j]  subject to        sum A[i,j] * x[j] <= 0,  for i = 0, ..., m-1        sum y[j] <= 3        y[j] = pwl(x[j]),        for j = 0, ..., n-1        x[j] free, y[j] >= 0,    for j = 0, ..., n-1  where pwl(x) = 0,     if x  = 0               = 1+|x|, if x != 0  Note   1. sum pwl(x[j]) <= b is to bound x vector and also to favor sparse x vector.      Here b = 3 means that at most two x[j] can be nonzero and if two, then      sum x[j] <= 1   2. pwl(x) jumps from 1 to 0 and from 0 to 1, if x moves from negative 0 to 0,      then to positive 0, so we need three points at x = 0. x has infinite bounds      on both sides, the piece defined with two points (-1, 2) and (0, 1) can      extend x to -infinite. Overall we can use five points (-1, 2), (0, 1),      (0, 0), (0, 1) and (1, 2) to define y = pwl(x)*/importcom.gurobi.gurobi.*;importjava.util.*;publicclassGCPWL{publicstaticvoidmain(String[]args){try{intn=5;intm=5;doublec[]={0.5,0.8,0.5,0.1,-1};doubleA[][]={{0,0,0,1,-1},{0,0,1,1,-1},{1,1,0,0,-1},{1,0,1,0,-1},{1,0,0,1,-1}};doublexpts[]={-1,0,0,0,1};doubleypts[]={2,1,0,1,2};// Env and modelGRBEnvenv=newGRBEnv();GRBModelmodel=newGRBModel(env);model.set(GRB.StringAttr.ModelName,"GCPWL");// Add variables, set bounds and obj coefficientsGRBVar[]x=model.addVars(n,GRB.CONTINUOUS);for(inti=0;i<n;i++){x[i].set(GRB.DoubleAttr.LB,-GRB.INFINITY);x[i].set(GRB.DoubleAttr.Obj,c[i]);}GRBVar[]y=model.addVars(n,GRB.CONTINUOUS);// Set objective to maximizemodel.set(GRB.IntAttr.ModelSense,GRB.MAXIMIZE);// Add linear constraintsfor(inti=0;i<m;i++){GRBLinExprle=newGRBLinExpr();for(intj=0;j<n;j++){le.addTerm(A[i][j],x[j]);}model.addConstr(le,GRB.LESS_EQUAL,0,"cx"+i);}GRBLinExprle1=newGRBLinExpr();for(intj=0;j<n;j++){le1.addTerm(1.0,y[j]);}model.addConstr(le1,GRB.LESS_EQUAL,3,"cy");// Add piecewise constraintsfor(intj=0;j<n;j++){model.addGenConstrPWL(x[j],y[j],xpts,ypts,"pwl"+j);}// Optimize modelmodel.optimize();for(intj=0;j<n;j++){System.out.println("x["+j+"] = "+x[j].get(GRB.DoubleAttr.X));}System.out.println("Obj: "+model.get(GRB.DoubleAttr.ObjVal));// Dispose of model and environmentmodel.dispose();env.dispose();}catch(GRBExceptione){System.out.println("Error code: "+e.getErrorCode()+". "+e.getMessage());}}}