public static bool PrevPermutation <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, T, bool> comp
)
{
var i = last;
if (first.IsEqual(last) || first.IsEqual(i = i.GetPrev()))
{
return(false);
}
while (true)
{
var ip1 = i;
if (comp(ip1.GetCurrent(), (i = i.GetPrev()).GetCurrent()))
{
var j = last;
while (comp((j = j.GetPrev()).GetCurrent(), i.GetCurrent()) == false)
{
}
Swap(i, j);
Reverse(ip1, last);
return(true);
}
if (i.IsEqual(first))
{
Reverse(first, last);
return(false);
}
}
}
public static ArrayIterator <T> Partition <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, bool> pred
)
{
while (first.NotEqual(last))
{
while (pred(first.GetCurrent()))
{
first = first.GetNext();
if (first.IsEqual(last))
{
return(first);
}
}
do
{
last = last.GetPrev();
if (first.IsEqual(last))
{
return(first);
}
} while (pred(last.GetCurrent()) == false);
first.Swap(last);
first = first.GetNext();
}
return(first);
}
public static void Sort <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, T, bool> comp
)
{
// Quicksort
if (first.IsEqual(last))
{
return;
}
var sep = first;
for (var i = first.GetNext(); i.NotEqual(last); i = i.GetNext())
{
if (comp(i.GetCurrent(), first.GetCurrent()))
{
sep = sep.GetNext();
sep.Swap(i);
}
}
first.Swap(sep);
first.Sort(sep, comp);
sep.GetNext().Sort(last, comp);
}
public static ArrayIterator <T> UniqueCopy <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
ArrayIterator <T> result,
Func <T, T, bool> pred
)
{
if (first.IsEqual(last))
{
return(last);
}
result.SetCurrent(first.GetCurrent());
while ((first = first.GetNext()).NotEqual(last))
{
var val = first.GetCurrent();
if (pred(result.GetCurrent(), val) == false)
{
result = result.GetNext();
result.SetCurrent(val);
}
}
result = result.GetNext();
return(result);
}
public static ArrayIterator <T> Search <T>(
this ArrayIterator <T> first1,
ArrayIterator <T> last1,
ArrayIterator <T> first2,
ArrayIterator <T> last2,
Func <T, T, bool> pred
)
{
if (first2.IsEqual(last2))
{
return(first1);
}
while (first1.NotEqual(last1))
{
var it1 = first1;
var it2 = first2;
while (pred(it1.GetCurrent(), it2.GetCurrent()))
{
it1 = it1.GetNext();
it2 = it2.GetNext();
if (it2.IsEqual(last2))
{
return(first1);
}
if (it1.IsEqual(last1))
{
return(last1);
}
}
first1 = first1.GetNext();
}
return(last1);
}
public static bool IsPermutation <T>(
this ArrayIterator <T> first1,
ArrayIterator <T> last1,
ArrayIterator <T> first2,
Func <T, T, bool> pred
)
{
first1.Mismatch(last1, first2, pred, out first1, out first2);
if (first1.IsEqual(last1))
{
return(true);
}
var last2 = first2;
last2 = last2.GetAdvanced(first1.Distance(last1));
for (var it1 = first1; it1.NotEqual(last1); it1 = it1.GetNext())
{
if (first1.Find(it1, it1.GetCurrent(), pred).IsEqual(it1))
{
var n = first2.Count(last2, it1.GetCurrent(), pred);
if (n == 0 || it1.Count(last1, it1.GetCurrent(), pred) != n)
{
return(false);
}
}
}
return(true);
}
public static void MinMaxElement <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, T, bool> comp,
out ArrayIterator <T> min,
out ArrayIterator <T> max
)
{
if (first.IsEqual(last))
{
min = last;
max = last;
}
min = first;
max = first;
while ((first = first.GetNext()).NotEqual(last))
{
if (comp(first.GetCurrent(), min.GetCurrent()))
{
min = first;
}
if (comp(max.GetCurrent(), first.GetCurrent()))
{
max = first;
}
}
}
public static ArrayIterator <T> Merge <T>(
this ArrayIterator <T> first1,
ArrayIterator <T> last1,
ArrayIterator <T> first2,
ArrayIterator <T> last2,
ArrayIterator <T> result,
Func <T, T, bool> comp
)
{
while (true)
{
if (first1.IsEqual(last1))
{
return(first2.Copy(last2, result));
}
if (first2.IsEqual(last2))
{
return(first1.Copy(last1, result));
}
if (comp(first2.GetCurrent(), first1.GetCurrent()))
{
result.SetCurrent(first2.GetCurrent());
first2 = first2.GetNext();
}
else
{
result.SetCurrent(first1.GetCurrent());
first1 = first1.GetNext();
}
result = result.GetNext();
}
}
public static ArrayIterator <T> MaxElement <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, T, bool> comp
)
{
if (first.IsEqual(last))
{
return(last);
}
var largest = first;
while ((first = first.GetNext()).NotEqual(last))
{
if (comp(largest.GetCurrent(), first.GetCurrent()))
{
largest = first;
}
}
return(largest);
}
public static ArrayIterator <T> IsSortedUntil <T>(
this ArrayIterator <T> first,
ArrayIterator <T> last,
Func <T, T, bool> comp
)
{
if (first.IsEqual(last))
{
return(first);
}
var next = first;
while ((next = next.GetNext()).NotEqual(last))
{
if (comp(next.GetCurrent(), first.GetCurrent()))
{
return(next);
}
first = first.GetNext();
}
return(last);
}
public static bool Includes <T>(
this ArrayIterator <T> first1,
ArrayIterator <T> last1,
ArrayIterator <T> first2,
ArrayIterator <T> last2,
Func <T, T, bool> comp
)
{
while (first2.NotEqual(last2))
{
if ((first1.IsEqual(last1)) || comp(first2.GetCurrent(), first1.GetCurrent()))
{
return(false);
}
if (comp(first1.GetCurrent(), first2.GetCurrent()) == false)
{
first2 = first2.GetNext();
}
first1 = first1.GetNext();
}
return(true);
}
public static void Rotate <T>(
this ArrayIterator <T> first,
ArrayIterator <T> middle,
ArrayIterator <T> last
)
{
var next = middle;
while (first.NotEqual(last))
{
first.Swap(next);
first = first.GetNext();
next = next.GetNext();
if (next.IsEqual(last))
{
next = middle;
}
else if (first.IsEqual(middle))
{
middle = next;
}
}
}
public static bool LexicographicalCompare <T>(
this ArrayIterator <T> first1,
ArrayIterator <T> last1,
ArrayIterator <T> first2,
ArrayIterator <T> last2,
Func <T, T, bool> comp
)
{
while (first1.NotEqual(last1))
{
if (first2.IsEqual(last2) || comp(first2.GetCurrent(), first1.GetCurrent()))
{
return(false);
}
else if (comp(first1.GetCurrent(), first2.GetCurrent()))
{
return(true);
}
first1 = first1.GetNext();
first2 = first2.GetNext();
}
return(first2.NotEqual(last2));
}