private void AddValue(int start, int end, int val, SegmentTreeNode node)
{
//if the new interval is completely contains the root of this sub tree
if (start <= node.Start && node.End <= end)
{
node.Booked += val;
node.Saved += val;
return;
}
int mid = (node.End + node.Start) / 2;
if (start <= mid)
{
if (node.Left == null)
{
node.Left = new SegmentTreeNode(node.Start, mid, 0, 0);
}
AddValue(start, Math.Min(mid, end), val, node.Left);
}
if (end >= mid + 1)
{
if (node.Right == null)
{
node.Right = new SegmentTreeNode(mid + 1, node.End, 0, 0);
}
AddValue(Math.Max(mid + 1, start), end, val, node.Right);
}
node.Saved = Math.Max(node.Left?.Saved ?? 0,
node.Right?.Saved ?? 0) + node.Booked;
}
public SegmentTree(int min, int max)
{
_root = new SegmentTreeNode(min, max, 0, 0);
}
