public void MoveBackwardTest()
{
int[] data = { 1, 2, 3 };
IList <int> lst = new List <int>();
int expectedCount = 3;
int actualCount = 0;
using (BidirectionalIterator <int> inputIterator = new BidirectionalIterator <int>(data))
{
using (IOutputIterator <int> outputIterator = new BackInsertIterator <int>(lst))
{
Algorithm.MoveBackward(inputIterator, outputIterator);
actualCount = lst.Count();
}
//whether the data is actually remove
Assert.IsTrue(inputIterator.Count() == 0);
}
Assert.IsTrue(expectedCount == actualCount);
bool isCorrectData = (lst[0] == 3 && lst[1] == 2 && lst[2] == 1);
Assert.IsTrue(isCorrectData);
}
/// <summary>
/// Copies elements from [begin,end) to [target-(end-begin), target), starting with *(target-1) = *(end-1),
/// and progressing backwards towards begin. Note that although elements are copied in reverse order, the order
/// of elements is not changed.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="begin"></param>
/// <param name="end"></param>
/// <param name="target"></param>
public static void CopyBackward <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end, BidirectionalIterator <T> targetEnd)
{
targetEnd = IteratorUtil.Clone(targetEnd);
end = IteratorUtil.Clone(end);
while (!begin.Equals(end))
{
end.MovePrev();
targetEnd.MovePrev();
targetEnd.Write(end.Read());
}
}
public static void ReverseCopy <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end, OutputIterator <T> dest)
{
end = IteratorUtil.Clone(end);
dest = IteratorUtil.Clone(dest);
while (!begin.Equals(end))
{
end.MovePrev();
dest.Write(end.Read());
dest.MoveNext();
}
}
public void ReverseTest()
{
int[] data = { 1, 2, 3 };
using (BidirectionalIterator <int> inputIterator = new BidirectionalIterator <int>(data))
{
Algorithm.Reverse(inputIterator);
Assert.IsTrue(inputIterator[0] == 3 &&
inputIterator[1] == 2 &&
inputIterator[2] == 1);
}
}
public static void Reverse <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end)
{
end = IteratorUtil.Clone(end);
begin = IteratorUtil.Clone(begin);
BidirectionalIterator <T> last = IteratorUtil.Clone(end);
last.MovePrev();
for (; !begin.Equals(last) && !begin.Equals(end); last.MovePrev(), end.MovePrev(), begin.MoveNext())
{
IteratorUtil.Swap(begin, last);
}
}
public static void Advance <T>(BidirectionalIterator <T> iter, int distance)
{
while (distance > 0)
{
iter.MoveNext();
--distance;
}
while (distance < 0)
{
iter.MovePrev();
++distance;
}
}
public void ReverseCopyTest()
{
int[] data = { 1, 2, 3 };
IList <int> lst = new List <int>();
using (IBidirectionalIterator <int> inputIterator = new BidirectionalIterator <int>(data))
{
using (IOutputIterator <int> outputIterator = new BackInsertIterator <int>(lst))
{
Algorithm.ReverseCopy(inputIterator, outputIterator);
}
Assert.IsTrue(lst[0] == 3 && lst[1] == 2 && lst[2] == 1);
}
}
public static void TestIEnumarable()
{
//Test custom simple collection with enumerator
MyCollection <int> collection = new MyCollection <int>(new [] { 1, 2, 3, 4 });
Console.WriteLine("MyCollection: ");
foreach (var n in collection)
{
Console.Write($"{n} ");
}
Console.WriteLine();
//Test Bidirectional iterator
LinkedList <int> intList = new LinkedList <int>();
for (int i = 0; i < 6; i++)
{
intList.AddLast(i);
}
BidirectionalIterator <int> bidirectionalIterator = new BidirectionalIterator <int>(intList, intList.First, TIterationDirection.Forward);
Console.WriteLine("Bidirectional iterator: ");
foreach (var n in bidirectionalIterator)
{
Console.Write($"{n} ");
if (n == 5) //change direction
{
bidirectionalIterator.Direction = TIterationDirection.Backward;
}
}
Console.WriteLine();
//Test Circular iterator
CircularIterator <int> circularIterator = new CircularIterator <int>(intList, intList.First);
int counter = 0;
Console.WriteLine("Circular iterator: ");
foreach (var n in circularIterator)
{
Console.Write($"{n} ");
if (counter++ == 20)
{
circularIterator.Stop();
}
}
}
public static bool NextPermutation <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(i_value, ii.Read()))
{
BidirectionalIterator <T> j = IteratorUtil.Clone(end);
for (j.MovePrev(); !func(i_value, j.Read()); 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);
}
}
}
static void Main()
{
LinkedList <int> intList = new LinkedList <int>();
for (int i = 1; i < 6; ++i)
{
intList.AddLast(i);
}
BidirectionalIterator <int> iter =
new BidirectionalIterator <int>(intList,
intList.First,
TIteratorDirection.Forward);
foreach (int n in iter)
{
Console.WriteLine(n);
if (n == 5)
{
iter.Direction = TIteratorDirection.Backward;
}
}
}
public static void ReverseCopy <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end, IList <T> target)
{
ReverseCopy(begin, end, IteratorUtil.Begin(target));
}
/// <summary>
/// Copies the items from a source IList to an output iterator in reverse order.
/// </summary>
/// <remarks>Note the subtle difference between CopyBackward and ReverseCopy. </remarks>
/// <remarks>
/// This method is a little different than its Copy counterpart. Copy takes an IEnumerable<T>, which is very loose. We require
/// an IList<T>. The reason is because .NET does not provide a way to iterate an enumerable collection in reverse. We do provide
/// a workaround (see the next method), but it is very ineffecient."/>
/// </remarks>
/// <typeparam name="T"></typeparam>
/// <param name="list"></param>
/// <param name="target"></param>
public static void CopyBackward <T>(IList <T> list, BidirectionalIterator <T> targetEnd)
{
CopyBackward(IteratorUtil.Begin(list), IteratorUtil.End(list), targetEnd);
}
/// <summary>
/// Copies elements from a source enumerable to an output iterator in reverse order
/// </summary>
/// <remarks>
/// Because .NET does not allow use to traverse an enumerator in reverse, we have to create a complete, temporary
/// copy of the input collection. This is terribly inefficient. Beware when using this routine with large collections.
/// </remarks>
/// <typeparam name="T"></typeparam>
/// <param name="enumerable"></param>
/// <param name="target"></param>
public static void CopyBackward <T>(IEnumerable <T> enumerable, BidirectionalIterator <T> targetEnd)
{
CopyBackward(new List <T>(enumerable), targetEnd);
}
public UnitGroup(IEnumerable <UnitSelector> units)
{
this.units = new BidirectionalIterator <UnitSelector>(units);
this.units.TryMoveNext();
}
public static bool NextPermutation <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end)
where T : IComparable <T>
{
return(NextPermutation(begin, end, Comparer <T> .Default));
}
public static void CopyBackward <T>(BidirectionalIterator <T> begin, BidirectionalIterator <T> end, IList <T> targetEnd)
{
CopyBackward(begin, end, IteratorUtil.End(targetEnd));
}
public static BidirectionalIterator <T> AdvanceCopy <T>(BidirectionalIterator <T> iter, int distance)
{
iter = IteratorUtil.Clone(iter);
Advance(iter, distance);
return(iter);
}