static void TestQuickSortAndMedian()
{
Random r = new Random();
List <ValueTuple <int, int> > list = new List <ValueTuple <int, int> >();
for (int i = 0; i < 100; i++)
{
int a = r.Next(1000);
list.Add(new ValueTuple <int, int>(a, 1000 - a));
}
var xMedian = list.Median(new XCoordinateComparer <int>());
var yMedian = list.Median(new YCoordinateComparer <int>());
var xSorted = QuickSort <int> .Sort(list, new XCoordinateComparer <int>());
var ySorted = QuickSort <int> .Sort(list, new YCoordinateComparer <int>());
}
/// <summary>
/// Finds median by quicksorting.
/// </summary>
/// <typeparam name="T">Type of ValueTuple.</typeparam>
/// <param name="list">List of ValueTuples.</param>
/// <param name="comparer">ValueTuple comparer to be used.</param>
/// <returns>Median ValueTuple.</returns>
public static ValueTuple <T, T> Median <T>(this List <ValueTuple <T, T> > list, IComparer <ValueTuple <T, T> > comparer)
{
var sorted = QuickSort <T> .Sort(list, comparer);
return(sorted[sorted.Count / 2]);
}
/// <summary>
/// Inserts a new value to tree.
/// </summary>
/// <param name="newvalue">2D point to be inserted</param>
/// <param name="currentCoordinate">Current coordinate to navigate by</param>
public void Insert(ValueTuple <TValue, TValue> newvalue, int currentCoordinate)
{
// for tree validity check
//SaveLastState(OperationType.INSERT);
lastOpVisitedNodes = 0;
if (Root == null)
{
lastOpVisitedNodes = 1;
Root = new RangeTreeNode <TValue>(newvalue, Alpha, currentCoordinate);
return;
}
var comparer = (currentCoordinate == 0) ? xComparer : yComparer;
var currentNode = Root;
var parent = Root;
// find a place for new leaf
while (currentNode != null)
{
lastOpVisitedNodes++;
parent = currentNode;
if (currentCoordinate == 0)
{
currentNode.OtherDimensionSubtree.Insert(newvalue, 1);
}
// greater
if (comparer.Compare(newvalue, currentNode.Value) > 0)
{
currentNode.SubtreeNodesCount++;
currentNode = currentNode.Right;
}
// lesser
else if (comparer.Compare(newvalue, currentNode.Value) < 0)
{
currentNode.SubtreeNodesCount++;
currentNode = currentNode.Left;
}
// equal
else
{
currentNode.AddMiddleSon(new RangeTreeNode <TValue>(newvalue, Alpha, currentCoordinate));
// we are done here, this cannot break the invariant
return;
}
}
// add the new leaf
RangeTreeNode <TValue> leaf = new RangeTreeNode <TValue>(newvalue, Alpha, currentCoordinate);
if (comparer.Compare(parent.Value, newvalue) > 0)
{
parent.SetLeftSon(leaf);
}
else
{
parent.SetRightSon(leaf);
}
parent.SubtreeNodesCount--;
// rebuild the unbalanced trees
currentNode = parent;
while (currentNode != null)
{
if (!currentNode.IsBalanced())
{
var nodes = QuickSort <TValue> .Sort(currentNode.GetSubtreeValuesInOrder(), yComparer);
var rebuild = Build(nodes, currentCoordinate);
// for x and y tree
lastOpVisitedNodes += (rebuild.SubtreeNodesCount);
// we rebuit entire tree
if (currentNode.Parent == null)
{
Root = rebuild;
currentNode = rebuild;
}
else
{
if (comparer.Compare(currentNode.Parent.Value, rebuild.Value) > 0)
{
currentNode.Parent.SetLeftSon(rebuild);
}
else
{
currentNode.Parent.SetRightSon(rebuild);
}
}
}
currentNode = currentNode.Parent;
}
}