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/*
* Copyright 2002 Adrian Thurston <thurston@complang.org>
*/
/* This file is part of Aapl.
*
* Aapl is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* Aapl 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.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Aapl; if not, write to the Free Software Foundation, Inc., 59
* Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _AAPL_BUBBLESORT_H
#define _AAPL_BUBBLESORT_H
#ifdef AAPL_NAMESPACE
namespace Aapl {
#endif
/**
* \addtogroup sort
* @{
*/
/**
* \class BubbleSort
* \brief Bubble sort an array of data.
*
* BubbleSort can be used to sort any array of objects of type T provided a
* compare class is given. BubbleSort is in-place. It does not require any
* temporary storage.
*
* Objects are not made aware that they are being moved around in memory.
* Assignment operators, constructors and destructors are never invoked by the
* sort.
*
* BubbleSort runs in O(n^2) time. It is most useful when sorting arrays that
* are nearly sorted. It is best when neighbouring pairs are out of place.
* BubbleSort is a stable sort, meaning that objects with the same key have
* their relative ordering preserved.
*/
/*@}*/
/* BubbleSort. */
template <class T, class Compare> class BubbleSort
: public Compare
{
public:
/* Sorting interface routine. */
void sort(T *data, long len);
};
/**
* \brief Bubble sort an array of data.
*/
template <class T, class Compare> void BubbleSort<T,Compare>::
sort(T *data, long len)
{
bool changed = true;
for ( long pass = 1; changed && pass < len; pass ++ ) {
changed = false;
for ( long i = 0; i < len-pass; i++ ) {
/* Do we swap pos with the next one? */
if ( compare( data[i], data[i+1] ) > 0 ) {
char tmp[sizeof(T)];
/* Swap the two items. */
memcpy( tmp, data+i, sizeof(T) );
memcpy( data+i, data+i+1, sizeof(T) );
memcpy( data+i+1, tmp, sizeof(T) );
/* Note that we made a change. */
changed = true;
}
}
}
}
#ifdef AAPL_NAMESPACE
}
#endif
#endif /* _AAPL_BUBBLESORT_H */
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