Method applyConflictGraphSubstitutions

highs/presolve/HPresolve.cpp:2488–2541

}

HPresolve::Result HPresolve::applyConflictGraphSubstitutions(
    HighsPostsolveStack& postsolve_stack, HighsInt& numDelCol) {
  HighsCliqueTable& cliquetable = mipsolver->mipdata_->cliquetable;
  HighsImplications& implications = mipsolver->mipdata_->implications;
  for (const auto& substitution : implications.substitutions) {
    if (colDeleted[substitution.substcol] || colDeleted[substitution.staycol])
      continue;

    ++numDelCol;

    postsolve_stack.doubletonEquation(
        -1, substitution.substcol, substitution.staycol, 1.0,
        -substitution.scale, substitution.offset,
        model->col_lower_[substitution.substcol],
        model->col_upper_[substitution.substcol], 0.0, false, false,
        HighsPostsolveStack::RowType::kEq, HighsEmptySlice());
    markColDeleted(substitution.substcol);
    substitute(substitution.substcol, substitution.staycol, substitution.offset,
               substitution.scale);
    HPRESOLVE_CHECKED_CALL(checkLimits(postsolve_stack));
  }

  implications.substitutions.clear();

  for (HighsCliqueTable::Substitution subst : cliquetable.getSubstitutions()) {
    if (colDeleted[subst.substcol] || colDeleted[subst.replace.col]) continue;

    double scale;
    double offset;

    ++numDelCol;

    if (subst.replace.val == 0) {
      scale = -1.0;
      offset = 1.0;
    } else {
      scale = 1.0;
      offset = 0.0;
    }

    postsolve_stack.doubletonEquation(
        -1, subst.substcol, subst.replace.col, 1.0, -scale, offset,
        model->col_lower_[subst.substcol], model->col_upper_[subst.substcol],
        0.0, false, false, HighsPostsolveStack::RowType::kEq,
        HighsEmptySlice());
    markColDeleted(subst.substcol);
    substitute(subst.substcol, subst.replace.col, offset, scale);
    HPRESOLVE_CHECKED_CALL(checkLimits(postsolve_stack));
  }

  cliquetable.getSubstitutions().clear();

  return Result::kOk;
}

void HPresolve::getRowPositions(HighsInt row,
                                std::vector<HighsInt>& myrowpositions) const {