private IntervalNode Find_Max(int x) //Find the Node with x-coordinate == x
{
IntervalNode node = root;
while (node != null)
{
if (node.value == x)
{
break;
}
if (x > node.value && node.right == null)
{
return(node);
}
if (x > node.value)
{
node = node.right;
}
else
{
node = node.left;
}
}
return(node);
}
public List <Interval> Q(Interval interval1, Interval interval2) //find all points at rectangle [x1, x2]x[y1,y2]
{
IntervalNode node = Find_Max(interval1.y);
List <Interval> result = node.Find_Points_In_Rectangle(interval1, interval2);
return(result);
}
private IntervalNode Build(int l, int r, IntervalNode node)
{
if (l > r)
{
return(null);
}
int mid = (r + l) / 2;
int value = sorted_list[mid].x;
node = new IntervalNode();
if (l == r)
{
node.value = value;
}
List <Interval> list = new List <Interval>();
for (int i = 0; i < sorted_list.Count; i++)
{
if (sorted_list[i].x <= value)
{
list.Add(sorted_list[i]);
}
}
node.AddList(list);
node.value = value;
if (l == 0 && r == sorted_list.Count - 1)
{
root = node;
}
node.left = Build(l, mid - 1, node.left);
node.right = Build(mid + 1, r, node.right);
return(node);
}
public List <Interval> sorted_list = new List <Interval>(); //sorted by x-coordinate
public RangeTree(List <Interval> list)
{
sorted_list = IntervalNode.SortByY(list, false);
Build(0, sorted_list.Count - 1, root);
}