/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* */ /* This file is part of the program and library */ /* SCIP --- Solving Constraint Integer Programs */ /* */ /* Copyright 2002-2022 Zuse Institute Berlin */ /* */ /* Licensed under the Apache License, Version 2.0 (the "License"); */ /* you may not use this file except in compliance with the License. */ /* You may obtain a copy of the License at */ /* */ /* http://www.apache.org/licenses/LICENSE-2.0 */ /* */ /* Unless required by applicable law or agreed to in writing, software */ /* distributed under the License is distributed on an "AS IS" BASIS, */ /* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */ /* See the License for the specific language governing permissions and */ /* limitations under the License. */ /* */ /* You should have received a copy of the Apache-2.0 license */ /* along with SCIP; see the file LICENSE. If not visit scipopt.org. */ /* */ /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /**@file heur_randrounding.h * @ingroup PRIMALHEURISTICS * @brief randomized LP rounding heuristic which also generates conflicts via an auxiliary probing tree * @author Gregor Hendel * * Randomized LP rounding uses a random variable from a uniform distribution * over [0,1] to determine whether the fractional LP value x should be rounded * up with probability x - floor(x) or down with probability ceil(x) - x. * * This implementation uses domain propagation techniques to tighten the variable domains after every * rounding step. * * @see: The most relevant publication is Raghavan & Thompson, * "Randomized rounding: A technique for provably good algorithms and algorithmic proofs", * Combinatorica 7 (4): 365–374 * 1987 */ /*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/ #ifndef __SCIP_HEUR_RANDROUNDING_H__ #define __SCIP_HEUR_RANDROUNDING_H__ #include "scip/def.h" #include "scip/type_retcode.h" #include "scip/type_scip.h" #ifdef __cplusplus extern "C" { #endif /** creates the rand rounding heuristic and includes it in SCIP * * @ingroup PrimalHeuristicIncludes */ SCIP_EXPORT SCIP_RETCODE SCIPincludeHeurRandrounding( SCIP* scip /**< SCIP data structure */ ); #ifdef __cplusplus } #endif #endif