public static T[] Sort(T[] array, SortDirection sortDirection = SortDirection.Ascending)
{
var comparer = new CustomComparer <T>(sortDirection, Comparer <T> .Default);
var k = array.Length / 2;
var j = 0;
while (k >= 1)
{
for (int i = k; i < array.Length; i = i + k, j = j + k)
{
if (comparer.Compare(array[i], array[j]) >= 0)
{
continue;
}
swap(array, i, j);
if (i <= k)
{
continue;
}
i -= k * 2;
j -= k * 2;
}
j = 0;
k /= 2;
}
return(array);
}
public void PriorityQueueStabilityTest()
{
CustomComparer <int> comparer = new CustomComparer <int>((a, b) => Comparer <int> .Default.Compare(a / 10, b / 10));
PriorityQueue <int, int> queue = new PriorityQueue <int, int>(comparer);
List <int> list = new List <int>();
Random random = new Random();
for (int i = 0; i < 100; i++)
{
int n = random.Next(100);
int j = 0;
while (j < list.Count && comparer.Compare(list[j], n) != 1)
{
j++;
}
list.Insert(j, n);
queue.Enqueue(n, n);
}
for (int i = 0; i < list.Count; i++)
{
int n = queue.Dequeue();
Assert.AreEqual(list[i], n);
}
}
/// <summary>
/// Merge two sorted arrays.
/// </summary>
private static void merge(Indexable <T> array, int leftStart, int middle, int rightEnd,
CustomComparer <T> comparer)
{
var newLength = rightEnd - leftStart + 1;
var result = new T[newLength];
int i = leftStart, j = middle + 1, k = 0;
//iteratively compare and pick min to result
while (i <= middle && j <= rightEnd)
{
if (comparer.Compare(array[i], array[j]) < 0)
{
result[k] = array[i];
i++;
}
else
{
result[k] = array[j];
j++;
}
k++;
}
//copy left overs
if (i <= middle)
{
for (var l = i; l <= middle; l++)
{
result[k] = array[l];
k++;
}
}
else
{
for (var l = j; l <= rightEnd; l++)
{
result[k] = array[l];
k++;
}
}
k = 0;
//now write back result
for (var g = leftStart; g <= rightEnd; g++)
{
array[g] = result[k];
k++;
}
}
public int Compare(T x, T y)
{
if (_comparer != null && x != null && y != null)
{
var result = _comparer.Compare(Property.GetValue(x), Property.GetValue(y));
if (Direction == ListSortDirection.Descending)
{
result = -result;
}
if (result != 0)
{
return(result);
}
}
return(_baseComparer?.Compare(x, y) ?? 0);
}
/// <summary>
/// Time complexity: O(n^2).
/// </summary>
public static Span <T> Sort(Span <T> array, SortDirection sortDirection = SortDirection.Ascending)
{
var comparer = new CustomComparer <T>(sortDirection, Comparer <T> .Default);
for (int i = 0; i < array.Length; i++)
{
//select the smallest item in sub array and move it to front
for (int j = i + 1; j < array.Length; j++)
{
if (comparer.Compare(array[j], array[i]) >= 0)
{
continue;
}
var temp = array[i];
array[i] = array[j];
array[j] = temp;
}
}
return(array);
}
private static void sort(Span <T> array, int startIndex, int endIndex, CustomComparer <T> comparer)
{
while (true)
{
//if only one element the do nothing
if (startIndex < 0 || endIndex < 0 || endIndex - startIndex < 1)
{
return;
}
//set the wall to the left most index
var wall = startIndex;
//pick last index element on array as comparison pivot
var pivot = array[endIndex];
//swap elements greater than pivot to the right side of wall
//others will be on left
for (var j = wall; j <= endIndex; j++)
{
if (comparer.Compare(pivot, array[j]) <= 0 && j != endIndex)
{
continue;
}
var temp = array[wall];
array[wall] = array[j];
array[j] = temp;
//increment to exclude the minimum element in subsequent comparisons
wall++;
}
//sort left
sort(array, startIndex, wall - 2, comparer);
//sort right
startIndex = wall;
}
}
/// <summary>
/// Time complexity: O(n^2).
/// </summary>
public static T[] Sort(T[] array, SortDirection sortDirection = SortDirection.Ascending)
{
var comparer = new CustomComparer <T>(sortDirection, Comparer <T> .Default);
for (int i = 0; i < array.Length - 1; i++)
{
for (int j = i + 1; j > 0; j--)
{
if (comparer.Compare(array[j], array[j - 1]) < 0)
{
var temp = array[j - 1];
array[j - 1] = array[j];
array[j] = temp;
}
else
{
break;
}
}
}
return(array);
}
/// <summary>
/// Time complexity: O(n^2).
/// </summary>
public static T[] Sort(T[] array, SortDirection sortDirection = SortDirection.Ascending)
{
var comparer = new CustomComparer <T>(sortDirection, Comparer <T> .Default);
var swapped = true;
while (swapped)
{
swapped = false;
for (int i = 0; i < array.Length - 1; i++)
{
//compare adjacent elements
if (comparer.Compare(array[i], array[i + 1]) > 0)
{
var temp = array[i];
array[i] = array[i + 1];
array[i + 1] = temp;
swapped = true;
}
}
}
return(array);
}
