sort_util.h

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/*
 * Copyright (c) 2011-2015:  G-CSC, Goethe University Frankfurt
 * Author: Martin Rupp
 * 
 * This file is part of UG4.
 * 
 * UG4 is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License version 3 (as published by the
 * Free Software Foundation) with the following additional attribution
 * requirements (according to LGPL/GPL v3 §7):
 * 
 * (1) The following notice must be displayed in the Appropriate Legal Notices
 * of covered and combined works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (2) The following notice must be displayed at a prominent place in the
 * terminal output of covered works: "Based on UG4 (www.ug4.org/license)".
 * 
 * (3) The following bibliography is recommended for citation and must be
 * preserved in all covered files:
 * "Reiter, S., Vogel, A., Heppner, I., Rupp, M., and Wittum, G. A massively
 *   parallel geometric multigrid solver on hierarchically distributed grids.
 *   Computing and visualization in science 16, 4 (2013), 151-164"
 * "Vogel, A., Reiter, S., Rupp, M., Nägel, A., and Wittum, G. UG4 -- a novel
 *   flexible software system for simulating pde based models on high performance
 *   computers. Computing and visualization in science 16, 4 (2013), 165-179"
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 */
 
#include <utility>
 
#ifndef __H__SORT_UTIL__
#define __H__SORT_UTIL__
 
 
template<typename TIndex, typename TValue>
struct SortStruct
{
  SortStruct() { }
  SortStruct(TIndex &i, TValue &v) : index(i), value(v) { }
 
  void set_value(TValue &val)
  {
    value = val;
  }
 
  TValue &get_value()
  {
    return value;
  }
 
  bool operator < (const SortStruct<TIndex, TValue> &other) const
  {
    return value < other.value;
  }
 
  TIndex index;
  TValue value;
};
 
 
 
template<typename TCompareValues, bool bReverse>
class CompareIndicesByClass
{
public:
  CompareIndicesByClass(const TCompareValues &compareValues) : m_compareValues(compareValues) { }
 
  template<typename TIndex>
  bool operator () (const TIndex &i, const TIndex &j) const
  {
    if(bReverse)
      return m_compareValues[i] > m_compareValues[j];
    else
      return m_compareValues[i] < m_compareValues[j];
  }
private:
  const TCompareValues &m_compareValues;
};
 
template<typename TCompareValues, typename TCompare>
class CompareIndicesByClass2
{
public:
  CompareIndicesByClass2(const TCompareValues &compareValues, TCompare comp) : m_compareValues(compareValues), m_comp(comp) { }
 
  template<typename TIndex>
  bool operator () (const TIndex &i, const TIndex &j) const
  {
    return m_comp(m_compareValues[i], m_compareValues[j]);
  }
private:
  const TCompareValues &m_compareValues;
  TCompare m_comp;
};
 
//  CompareIndicesBy
template<typename TCompareValues>
inline CompareIndicesByClass<TCompareValues, false> CompareIndicesBy(const TCompareValues &values)
{
  return CompareIndicesByClass<TCompareValues, false>(values);
}
 
template<typename TCompareValues>
inline CompareIndicesByClass<TCompareValues, true> CompareIndicesReversedBy(const TCompareValues &values)
{
  return CompareIndicesByClass<TCompareValues, true>(values);
}
 
template<typename TCompareValues, typename TCompare>
inline CompareIndicesByClass2<TCompareValues, TCompare> CompareIndicesBy(const TCompareValues &values, TCompare comp)
{
  return CompareIndicesByClass2<TCompareValues, TCompare>(values, comp);
}
 
 
template<typename TCompareValues>
void GetSortedIndices(std::vector<size_t> &indices, const TCompareValues &values, bool bReverse=false)
{
  indices.resize(values.size());
  for(size_t i=0; i<indices.size(); i++) indices[i] = i;
  if(bReverse)
    std::sort(indices.begin(), indices.end(), CompareIndicesByClass<TCompareValues, true>(values));
  else
    std::sort(indices.begin(), indices.end(), CompareIndicesByClass<TCompareValues, false>(values));
}
 
template<typename TCompareValues, typename TCompare>
void GetSortedIndices(std::vector<size_t> &indices, const TCompareValues &values, TCompare comp)
{
  indices.resize(values.size());
  for(size_t i=0; i<indices.size(); i++) indices[i] = i;
  std::sort(indices.begin(), indices.end(), CompareIndicesByClass2<TCompareValues, TCompare>(values, comp));
}
 
template<typename TCompareValues, typename TCompare>
std::vector<size_t> GetSortedIndices(const TCompareValues &values, TCompare comp)
{
  std::vector<size_t> indices(values.size());
  GetSortedIndices(indices, values, comp);
  return indices;
}
 
template<typename TCompareValues>
std::vector<size_t> GetSortedIndices(const TCompareValues &values)
{
  std::vector<size_t> indices(values.size());
  GetSortedIndices(indices, values);
  return indices;
}
 
 
 
inline bool boolstrcmp(const char *a, const char *b)
{
  return strcmp(a, b) < 0;
}
 
inline bool boolstrcmpReversed(const char *a, const char *b)
{
  return strcmp(a, b) > 0;
}
 
// end group ugbase_common_util
 
#endif