fei_ArrayUtils.hpp

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#ifndef _fei_ArrayUtils_hpp_
#define _fei_ArrayUtils_hpp_

/*--------------------------------------------------------------------*/
/*    Copyright 2005 Sandia Corporation.                              */
/*    Under the terms of Contract DE-AC04-94AL85000, there is a       */
/*    non-exclusive license for use of this work by or on behalf      */
/*    of the U.S. Government.  Export of this program may require     */
/*    a license from the United States Government.                    */
/*--------------------------------------------------------------------*/

#include "fei_fwd.hpp"

#include <algorithm>

namespace fei {


  template<typename T>
  inline int lowerBound(const T& item,
     const T* list,
     int len)
  {
    //The correctness of this function is tested in
    // fei/test_utils/test_misc.cpp, in test_misc::serialtest2().

    if (len < 1) return 0;

    unsigned start = 0;
    unsigned end = len - 1;

    while(end - start > 23) {
      unsigned mid = (start + end) >> 1;
      if (list[mid] < item) start = mid;
      else end = mid;
    }

    while (start+7<=end ) {
      if ( item <= list[start+0] ) return start+0;
      if ( item <= list[start+1] ) return start+1;
      if ( item <= list[start+2] ) return start+2;
      if ( item <= list[start+3] ) return start+3;
      if ( item <= list[start+4] ) return start+4;
      if ( item <= list[start+5] ) return start+5;
      if ( item <= list[start+6] ) return start+6;
      if ( item <= list[start+7] ) return start+7;
      start+=8;
    }

    while (start<=end && item > list[start] ) 
      start++;

    return(start);
  }

  template<typename T>
  inline int binarySearch(const T& item,
        const T* list,
        int len)
    {
      int result = lowerBound(item,list,len);
      if ( result < len && item == list[result] )
  return result;
      return -1;
    }

  template<typename T>
  inline void insertion_sort_with_companions(int len, int* array, T* companions)
    {
      int i, j, index;
      T companion;

      for (i=1; i < len; i++) {
        index = array[i];
        companion = companions[i];
        j = i;
        while ((j > 0) && (array[j-1] > index))
        {
          array[j] = array[j-1];
          companions[j] = companions[j-1];
          j = j - 1;
        }
        array[j] = index;
        companions[j] = companion;
      }
    }


  template<typename T>
  inline int binarySearch(const T& item,
         const T* list,
         int len,
         int& insertPoint)
    {
      //The correctness of this function is tested in src/utils/test_Set.C,
      //in the function test_Set::test2.
      insertPoint = lowerBound(item,list,len);
      if ( insertPoint < len && item == list[insertPoint] )
  return insertPoint;
      return -1;
    }

  template<typename T>
  inline int binarySearch(const T& item, const std::vector<T>& list, int& insertPoint)
    {
      if (list.size() == 0) {
        insertPoint = 0;
        return(-1);
      }
      return( binarySearch(item, &list[0], list.size(), insertPoint) );
    }

  template<typename T>
  inline int binarySearch(const T& item, const std::vector<T>& list)
    {
      if (list.size() == 0) return(-1);
      return( binarySearch(item, &list[0], list.size()) );
    }

  template<typename T>
  inline int binarySearch(const T& item, const T* list, int /*listLength*/,
         int start, int end, int& insertPoint)
    {
      int result = binarySearch(item,list+start,end-start+1,insertPoint);
      if ( result >= 0 )
  return result+start;
      insertPoint+= start;
      return -1;
    }

  template<typename T>
  inline int binarySearch(int numItems, const T* items, int* offsets,
         const T* list, int listLength)
    {
      int i;
      if (numItems < 1 || listLength < 1) {
        if (listLength < 1) {
          for(i=0; i<numItems; ++i) offsets[i] = -1;
        }
      }

      int tmp, start = 0;
      int end = listLength -1;
      int insertPoint = -1;
      for(i=0; i<numItems; ++i) {
        tmp = binarySearch(items[i], list, listLength, start, end, insertPoint);
        start = tmp > -1 ? tmp : insertPoint;
        offsets[i] = tmp;
      }

      return(0);
    }

  template<class T>
  inline int sortedListInsert(const T& item, std::vector<T>& list)
    {
      typename std::vector<T>::iterator iter =
        std::lower_bound(list.begin(), list.end(), item);

      if (iter == list.end() || *iter != item) {
        iter = list.insert(iter, item);
        return( iter - list.begin() );
      }

      return(-1);
    }

  template<class T>
  inline int sortedListInsert(const T& item, T*& list, int& len, int& allocLen)
    {
      int i, insertPoint = -1;
      int index = binarySearch(item, list, len, insertPoint);
      if (index < 0) {
        if (len >= allocLen) {
          allocLen = len+2;
          T* newlist = new T[allocLen];
          for(i=0; i<insertPoint; ++i) newlist[i] = list[i];
          newlist[insertPoint] = item;
          for(i=insertPoint; i<len; ++i) newlist[i+1] = list[i];
          delete [] list;
          list = newlist;
        }
        else {
          for(i=len; i>insertPoint; --i) {
            list[i] = list[i-1];
          }
          list[insertPoint] = item;
        }
        ++len;
        return(insertPoint);
      }

      return(-1);
    }

  template<class T>
  inline int listInsert(const T& item, int offset, T*& list,
       int& usedLength, int& allocatedLength,
       int allocChunkSize=200)
    {
      if (offset < 0 || offset > usedLength) {
        return(-1);
      }

      if (usedLength < allocatedLength) {
        for(int i=usedLength; i>offset; --i) {
          list[i] = list[i-1];
        }
        list[offset] = item;
        ++usedLength;
        return(0);
      }

      T* newlist = new T[allocatedLength+allocChunkSize];

      allocatedLength += allocChunkSize;
      int i;
      for(i=0; i<offset; ++i) {
        newlist[i] = list[i];
      }

      newlist[offset] = item;

      for(i=offset+1; i<=usedLength; ++i) {
        newlist[i] = list[i-1];
      }

      ++usedLength;
      delete [] list;
      list = newlist;
      return(0);
    }

  template<class T>
  inline int searchList(const T& item, const T* list, int len)
    {
      for(int i=0; i<len; ++i) {
        if (list[i] == item) {
          return(i);
        }
      }
      return(-1);
    }

} //namespace fei

#endif // _fei_ArrayUtils_hpp_