public static bool PrevPermutation <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end,
Functional.BinaryPredicate <T> func)
{
if (begin.Equals(end))
{
return(false);
}
if (IteratorUtil.IsOneElementRange(begin, end))
{
return(false);
}
BidirectionalIterator <T> i = IteratorUtil.Clone(end);
i.MovePrev();
for (;;)
{
BidirectionalIterator <T> ii = IteratorUtil.Clone(i);
i.MovePrev();
T i_value = i.Read();
if (func(ii.Read(), i_value))
{
BidirectionalIterator <T> j = IteratorUtil.Clone(end);
for (j.MovePrev(); !func(j.Read(), i_value); j.MovePrev())
{
;
}
IteratorUtil.Swap(i, j);
Reverse(ii, end);
return(true);
}
if (i.Equals(begin))
{
Reverse(begin, end);
return(false);
}
}
}
public static bool NextPermutation <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end, IComparer <T> comparer)
{
if (begin.Equals(end))
{
return(false);
}
if (IteratorUtil.IsOneElementRange(begin, end))
{
return(false);
}
BidirectionalIterator <T> i = IteratorUtil.Clone(end);
i.MovePrev();
for (;;)
{
BidirectionalIterator <T> ii = IteratorUtil.Clone(i);
i.MovePrev();
T i_value = i.Read();
if (comparer.Compare(i_value, ii.Read()) == -1)
{
BidirectionalIterator <T> j = IteratorUtil.Clone(end);
for (j.MovePrev(); comparer.Compare(i_value, j.Read()) != -1; j.MovePrev())
{
;
}
IteratorUtil.Swap(i, j);
Reverse(ii, end);
return(true);
}
if (i.Equals(begin))
{
Reverse(begin, end);
return(false);
}
}
}
public static ForwardIterator <T> Search <T>(ForwardIterator <T> begin, ForwardIterator <T> end,
ForwardIterator <T> searchBegin, ForwardIterator <T> searchEnd,
IEqualityComparer <T> comparer)
{
if (begin.Equals(end))
{
return(null);
}
if (searchBegin.Equals(searchEnd))
{
return(null);
}
begin = IteratorUtil.Clone(begin);
searchBegin = IteratorUtil.Clone(searchBegin);
if (IteratorUtil.IsOneElementRange(searchBegin, searchEnd))
{
return(Find(begin, end, searchBegin.Read(), comparer));
}
T firstSearchElement = searchBegin.Read();
while (!begin.Equals(end))
{
begin = Find(begin, end, firstSearchElement, comparer);
if (begin == null)
{
return(null);
}
ForwardIterator <T> iter = IteratorUtil.Clone(begin);
iter.MoveNext();
if (iter.Equals(end))
{
return(null);
}
ForwardIterator <T> searchIter = IteratorUtil.Clone(searchBegin);
searchIter.MoveNext();
while (comparer.Equals(iter.Read(), searchIter.Read()))
{
searchIter.MoveNext();
if (searchIter.Equals(searchEnd))
{
return(begin);
}
iter.MoveNext();
if (iter.Equals(end))
{
return(null);
}
}
begin.MoveNext();
}
return(null);
}
public static ForwardIterator <T> Search <T>(ForwardIterator <T> begin, ForwardIterator <T> end,
ForwardIterator <T> searchBegin, ForwardIterator <T> searchEnd)
where T : IEquatable <T>
{
return(Search(begin, end, searchBegin, searchEnd, EqualityComparer <T> .Default));
#if NEVER
if (begin.Equals(end))
{
return(null);
}
if (searchBegin.Equals(searchEnd))
{
return(null);
}
begin = IteratorUtil.Clone(begin);
searchBegin = IteratorUtil.Clone(searchBegin);
if (IteratorUtil.IsOneElementRange(searchBegin, searchEnd))
{
return(Find(begin, end, searchBegin.Read()));
}
T firstSearchElement = searchBegin.Read();
while (!begin.Equals(end))
{
begin = Find(begin, end, firstSearchElement);
if (begin == null)
{
return(null);
}
ForwardIterator <T> iter = IteratorUtil.Clone(begin);
iter.MoveNext();
if (iter.Equals(end))
{
return(null);
}
ForwardIterator <T> searchIter = IteratorUtil.Clone(searchBegin);
searchIter.MoveNext();
while (iter.Read().Equals(searchIter.Read()))
{
searchIter.MoveNext();
if (searchIter.Equals(searchEnd))
{
return(begin);
}
iter.MoveNext();
if (iter.Equals(end))
{
return(null);
}
}
begin.MoveNext();
}
return(null);
#endif
}
