static public ArraySlice <T> EqualSlice <T> (this T[] arr, ref T val, RefComparison <T> comp)
{
int b = 0, end = arr.Length;
return(arr.EqualRange(ref b, ref end, ref val, comp) ?
new ArraySlice <T>(arr, b, end) :
ArraySlice <T> .Empty);
}
private static void SwapIfGreaterWithItems <T>(T[] keys, RefComparison <T> comparison, int a, int b)
{
if ((a != b) && (comparison(ref keys[a], ref keys[b]) > 0))
{
T local = keys[a];
keys[a] = keys[b];
keys[b] = local;
}
}
internal static void QuickSort <T>(T[] keys, int left, int right, RefComparison <T> comparison)
{
do
{
int a = left;
int b = right;
int mid = a + ((b - a) >> 1);
SwapIfGreaterWithItems(keys, comparison, a, mid);
SwapIfGreaterWithItems(keys, comparison, a, b);
SwapIfGreaterWithItems(keys, comparison, mid, b);
T y = keys[mid];
do
{
while (comparison(ref keys[a], ref y) < 0)
{
a++;
}
while (comparison(ref y, ref keys[b]) < 0)
{
b--;
}
if (a > b)
{
break;
}
if (a < b)
{
T local2 = keys[a];
keys[a] = keys[b];
keys[b] = local2;
}
a++;
b--;
}while (a <= b);
if ((b - left) <= (right - a))
{
if (left < b)
{
QuickSort(keys, left, b, comparison);
}
left = a;
}
else
{
if (a < right)
{
QuickSort(keys, a, right, comparison);
}
right = b;
}
}while (left < right);
}
static public bool EqualRange <T> (
this T[] arr, ref int begin, ref int end, ref T val, RefComparison <T> comp)
{
int lo = arr.LowerBound(begin, end, ref val, comp);
if (lo == end)
{
begin = end;
}
else if (lo == begin && comp(ref arr[begin], ref val) > 0)
{ //TODO
end = begin;
}
else
{
end = arr.UpperBound(begin = lo, end, ref val, comp);
}
return(begin != end);
}
static public int UpperBound <T> (this T[] arr, ref T val, RefComparison <T> comp)
{
return(arr.UpperBound(0, arr.Length, ref val, comp));
}
static public int UpperBound <T> (this T[] arr, int begin, int end, ref T val, RefComparison <T> comp)
{
while (begin < end)
{
int mid = (begin + end) / 2;
if (comp(ref arr[mid], ref val) <= 0)
{
begin = mid + 1;
}
else
{
end = mid;
}
}
return(begin);
}
