122 lines
4.1 KiB
C++
122 lines
4.1 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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// Cryptarithmetic puzzle
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//
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// First attempt to solve equation CP + IS + FUN = TRUE
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// where each letter represents a unique digit.
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//
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// This problem has 72 different solutions in base 10.
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// [START import]
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#include <stdlib.h>
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#include <cstdint>
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#include "absl/base/log_severity.h"
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#include "absl/log/globals.h"
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#include "ortools/base/init_google.h"
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#include "ortools/base/logging.h"
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#include "ortools/sat/cp_model.h"
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#include "ortools/sat/cp_model.pb.h"
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#include "ortools/sat/cp_model_solver.h"
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#include "ortools/sat/model.h"
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#include "ortools/sat/sat_parameters.pb.h"
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#include "ortools/util/sorted_interval_list.h"
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// [END import]
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namespace operations_research {
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namespace sat {
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void CPIsFunSat() {
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// Instantiate the solver.
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// [START model]
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CpModelBuilder cp_model;
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// [END model]
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// [START variables]
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const int64_t kBase = 10;
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// Define decision variables.
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Domain digit(0, kBase - 1);
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Domain non_zero_digit(1, kBase - 1);
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IntVar c = cp_model.NewIntVar(non_zero_digit).WithName("C");
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IntVar p = cp_model.NewIntVar(digit).WithName("P");
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IntVar i = cp_model.NewIntVar(non_zero_digit).WithName("I");
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IntVar s = cp_model.NewIntVar(digit).WithName("S");
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IntVar f = cp_model.NewIntVar(non_zero_digit).WithName("F");
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IntVar u = cp_model.NewIntVar(digit).WithName("U");
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IntVar n = cp_model.NewIntVar(digit).WithName("N");
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IntVar t = cp_model.NewIntVar(non_zero_digit).WithName("T");
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IntVar r = cp_model.NewIntVar(digit).WithName("R");
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IntVar e = cp_model.NewIntVar(digit).WithName("E");
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// [END variables]
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// [START constraints]
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// Define constraints.
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cp_model.AddAllDifferent({c, p, i, s, f, u, n, t, r, e});
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// CP + IS + FUN = TRUE
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cp_model.AddEquality(
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c * kBase + p + i * kBase + s + f * kBase * kBase + u * kBase + n,
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kBase * kBase * kBase * t + kBase * kBase * r + kBase * u + e);
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// [END constraints]
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// [START solution_printer]
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Model model;
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int num_solutions = 0;
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model.Add(NewFeasibleSolutionObserver([&](const CpSolverResponse& response) {
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LOG(INFO) << "Solution " << num_solutions;
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LOG(INFO) << "C=" << SolutionIntegerValue(response, c) << " "
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<< "P=" << SolutionIntegerValue(response, p) << " "
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<< "I=" << SolutionIntegerValue(response, i) << " "
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<< "S=" << SolutionIntegerValue(response, s) << " "
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<< "F=" << SolutionIntegerValue(response, f) << " "
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<< "U=" << SolutionIntegerValue(response, u) << " "
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<< "N=" << SolutionIntegerValue(response, n) << " "
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<< "T=" << SolutionIntegerValue(response, t) << " "
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<< "R=" << SolutionIntegerValue(response, r) << " "
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<< "E=" << SolutionIntegerValue(response, e);
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num_solutions++;
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}));
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// [END solution_printer]
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// [START solve]
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// Tell the solver to enumerate all solutions.
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SatParameters parameters;
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parameters.set_enumerate_all_solutions(true);
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model.Add(NewSatParameters(parameters));
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const CpSolverResponse response = SolveCpModel(cp_model.Build(), &model);
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LOG(INFO) << "Number of solutions found: " << num_solutions;
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// [END solve]
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// Statistics.
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// [START statistics]
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LOG(INFO) << "Statistics";
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LOG(INFO) << CpSolverResponseStats(response);
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// [END statistics]
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}
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} // namespace sat
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} // namespace operations_research
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int main(int argc, char* argv[]) {
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InitGoogle(argv[0], &argc, &argv, true);
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absl::SetStderrThreshold(absl::LogSeverityAtLeast::kInfo);
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operations_research::sat::CPIsFunSat();
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return EXIT_SUCCESS;
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}
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// [END program]
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