private static int Partition <T>(T[] arr, int left, int right, Comparator.IComparable <T> comparer)
{
int i = left, j = right;
T tmp;
T pivot = arr[(left + right) / 2];
while (i <= j)
{
while (comparer.Compare(arr[i], pivot) == -1)
{
i++;
}
while (comparer.Compare(arr[j], pivot) == 1)
{
j--;
}
if (i <= j)
{
tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
i++;
j--;
}
}
return(i);
}
public static int DoSearch <T>(T[] array, int left, int right, T x, Comparator.IComparable <T> comparer = null)
{
// #############################
// check null & type |
// ^
////Type arrayType = A.GetType();
////arrayType.GetInterface("IComparer");
array.ToSort(0, array.Length - 1, comparer);
return(Search(array, left, right, x, comparer));
}
internal static void ToSort <T>(this T[] arr, int left, int right, Comparator.IComparable <T> comparer)
{
int index = Partition(arr, left, right, comparer);
if (left < index - 1)
{
ToSort(arr, left, index - 1, comparer);
////arr.ToSort(left, index - 1);
}
if (index < right)
{
ToSort(arr, index, right, comparer);
////arr.ToSort(index, right);
}
}
public static int Search <T>(T[] array, int left, int right, T x, Comparator.IComparable <T> comparer)
{
if (left > right || comparer.Compare(x, array[left]) == -1 /*x < A[left]*/ || comparer.Compare(x, array[left]) == 1 /*x > A[right]*/)
{
return(-1);
}
int mid = left + ((right - left) / 2);
if (comparer.Compare(x, array[mid]) == 0)
{
return(mid);
}
if (comparer.Compare(x, array[left]) == -1)
{
return(Search(array, left, mid - 1, x, comparer));
}
else
{
return(Search(array, mid + 1, right, x, comparer));
}
}
