|
//-----------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//-----------------------------------------------------------------------------
namespace System.Activities.Validation
{
using System.Collections;
using System.Collections.Generic;
using System.Text;
static class ExtensionMethods
{
public static bool IsNullOrEmpty(this ICollection c)
{
return (c == null || c.Count == 0);
}
public static string AsCommaSeparatedValues(this IEnumerable<string> c)
{
StringBuilder sb = new StringBuilder();
foreach (string s in c)
{
if (!string.IsNullOrEmpty(s))
{
if (sb.Length == 0)
{
sb.Append(s);
}
else
{
sb.Append(", ");
sb.Append(s);
}
}
}
return sb.ToString();
}
public static int BinarySearch<T>(this IList<T> items, T value, IComparer<T> comparer)
{
return BinarySearch(items, 0, items.Count, value, comparer);
}
public static void QuickSort<T>(this IList<T> items, IComparer<T> comparer)
{
QuickSort(items, 0, items.Count - 1, comparer);
}
static int BinarySearch<T>(IList<T> items, int startIndex, int length, T value, IComparer<T> comparer)
{
int start = startIndex;
int end = (startIndex + length) - 1;
while (start <= end)
{
int mid = start + ((end - start) >> 1);
int result = comparer.Compare(items[mid], value);
if (result == 0)
{
return mid;
}
if (result < 0)
{
start = mid + 1;
}
else
{
end = mid - 1;
}
}
return ~start;
}
static void QuickSort<T>(IList<T> items, int startIndex, int endIndex, IComparer<T> comparer)
{
Stack<int> bounds = new Stack<int>();
do
{
if (bounds.Count != 0)
{
endIndex = bounds.Pop();
startIndex = bounds.Pop();
}
T pivot = items[startIndex];
int pivotIndex = startIndex;
for (int i = startIndex + 1; i <= endIndex; i++)
{
if (comparer.Compare(pivot, items[i]) > 0)
{
pivotIndex++;
if (pivotIndex != i)
{
items.Swap(pivotIndex, i);
}
}
}
if (startIndex != pivotIndex)
{
items.Swap(startIndex, pivotIndex);
}
if (pivotIndex + 1 < endIndex)
{
bounds.Push(pivotIndex + 1);
bounds.Push(endIndex);
}
if (startIndex < pivotIndex - 1)
{
bounds.Push(startIndex);
bounds.Push(pivotIndex - 1);
}
} while (bounds.Count != 0);
}
static void Swap<T>(this IList<T> items, int i, int j)
{
T temp = items[i];
items[i] = items[j];
items[j] = temp;
}
}
}
|