4f381f6d07
* bump abseil to 20250814 * bump protobuf to v32.0 * cmake: add ccache auto support * backport flatzinc, math_opt and sat update
85 lines
2.7 KiB
C#
85 lines
2.7 KiB
C#
// Copyright 2010-2025 Google LLC
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// [START program]
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using System;
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using Google.OrTools.Sat;
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using Google.OrTools.Util;
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public class VarArraySolutionPrinter : CpSolverSolutionCallback
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{
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public VarArraySolutionPrinter(IntVar[] variables)
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{
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variables_ = variables;
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}
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public override void OnSolutionCallback()
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{
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{
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foreach (IntVar v in variables_)
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{
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Console.Write(String.Format("{0}={1} ", v.ToString(), Value(v)));
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}
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Console.WriteLine();
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}
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}
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private IntVar[] variables_;
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}
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public class EarlinessTardinessCostSampleSat
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{
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static void Main()
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{
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long earliness_date = 5;
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long earliness_cost = 8;
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long lateness_date = 15;
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long lateness_cost = 12;
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// Create the CP-SAT model.
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CpModel model = new CpModel();
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// Declare our primary variable.
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IntVar x = model.NewIntVar(0, 20, "x");
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// Create the expression variable and implement the piecewise linear
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// function.
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//
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// \ /
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// \______/
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// ed ld
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//
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long large_constant = 1000;
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IntVar expr = model.NewIntVar(0, large_constant, "expr");
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// Link together expr and x through s1, s2, and s3.
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model.AddMaxEquality(expr, new LinearExpr[] { earliness_cost * (earliness_date - x), model.NewConstant(0),
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lateness_cost * (x - lateness_date) });
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// Search for x values in increasing order.
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model.AddDecisionStrategy(new IntVar[] { x }, DecisionStrategyProto.Types.VariableSelectionStrategy.ChooseFirst,
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DecisionStrategyProto.Types.DomainReductionStrategy.SelectMinValue);
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// Create the solver.
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CpSolver solver = new CpSolver();
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// Force solver to follow the decision strategy exactly.
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// Tell the solver to search for all solutions.
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solver.StringParameters = "search_branching:FIXED_SEARCH, enumerate_all_solutions:true";
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VarArraySolutionPrinter cb = new VarArraySolutionPrinter(new IntVar[] { x, expr });
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solver.Solve(model, cb);
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}
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}
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// [END program]
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