public static List <T> QuickSort <T>(this List <T> list, ComparatorDelegate <T> comparator)
{
List <T> retVal = new List <T>(list);
retVal.QuickSort(comparator, 0, list.Count - 1);
return(retVal);
//if (list.Count <= 1) {
// return list;
//}
//T median = list[0];
//List<T> ltList = new List<T>();
//List<T> equalList = new List<T>();
//List<T> gtList = new List<T>();
//foreach (T t in list) {
// if (comparator(t, median) < 0) {
// ltList.Add(t);
// }
// if (comparator(t, median) == 0) {
// equalList.Add(t);
// }
// else if (comparator(t, median) > 0) {
// gtList.Add(t);
// }
//}
//List<T> sortedLtList = QuickSort(ltList, comparator);
//List<T> sortedGtList = QuickSort(gtList, comparator);
//sortedLtList.AddRange(equalList);
//sortedLtList.AddRange(sortedGtList);
//return sortedLtList;
}
public static List <T> QuickSort <T>(List <T> list, ComparatorDelegate <T> comparator)
{
if (list.Count <= 1)
{
return(list);
}
T median = list[0];
List <T> ltList = new List <T>();
List <T> equalList = new List <T>();
List <T> gtList = new List <T>();
foreach (T t in list)
{
if (comparator(t, median) < 0)
{
ltList.Add(t);
}
if (comparator(t, median) == 0)
{
equalList.Add(t);
}
else if (comparator(t, median) > 0)
{
gtList.Add(t);
}
}
List <T> sortedLtList = QuickSort(ltList, comparator);
List <T> sortedGtList = QuickSort(gtList, comparator);
sortedLtList.AddRange(equalList);
sortedLtList.AddRange(sortedGtList);
return(sortedLtList);
}
public LevelDBComparator(string name, ComparatorDelegate comparator)
{
Name = name;
Comparator = comparator;
namePointer = Marshal.StringToHGlobalAnsi(name);
comparatorName = delegate { return((void *)namePointer); };
this.comparator = (_, k1, klen1, k2, klen2) => {
return(Comparator(new ReadOnlySpan <byte>(k1, (int)klen1), new ReadOnlySpan <byte>(k2, (int)klen2)));
};
nativePointer = Native.comparator_create(null, emptyDestructor, this.comparator, comparatorName);
}
private static void QuickSort <T>(this List <T> list, ComparatorDelegate <T> comparator, int low, int high)
{
if (low >= high)
{
return;
}
T median = list[high];
int i = low;
for (int j = low; j < high; j++)
{
if (comparator(list[j], median) < 0)
{
list.Swap(i, j);
i++;
}
}
list.Swap(i, high);
list.QuickSort(comparator, low, i - 1);
list.QuickSort(comparator, i + 1, high);
}
