private static List <IIntervalable> FindOverlapRange(IntervalNode node, IIntervalable interval)
{
if (node != null)
{
return(node.GetOverlap(interval));
}
return(new List <IIntervalable>());
}
/// <summary>
/// 将备选区间添加到指定列表中
/// </summary>
/// <param name="interval">备选区间不能与指定区间相等</param>
/// <param name="list"></param>
/// <param name="candidates"></param>
private void AddOverlaps(IIntervalable interval, List <IIntervalable> list, List <IIntervalable> candidates)
{
for (int i = 0; i < candidates.Count; i++)
{
var inter = candidates[i];
if (!inter.Equals(interval))
{
list.Add(inter);
}
}
}
/// <summary>
/// 在当前节点的区间集合中寻找与指定区间重叠的
/// </summary>
/// <param name="interval">一个区间，与该区间重叠</param>
/// <param name="direction">方向，表示是左边还是右边</param>
/// <returns></returns>
private List <IIntervalable> Check4Overlap(IIntervalable interval, Direction direction)
{
var overlaps = new List <IIntervalable>();
foreach (var inter in _intervals)
{
if (direction == Direction.LEFT) // 检测与指定区间是否右边重叠: interval ________________ |_point|
{ // ______________________ inter (_point 处于 inter区间里面)
if (inter.Start <= interval.End)
{
overlaps.Add(inter);
}
}
else // 检测与指定区间是否左边重叠: |_point| ________________ interval
{ // ___________________________ inter (_point 处于 inter区间里面)
if (inter.End >= interval.Start)
{
overlaps.Add(inter);
}
}
}
return(overlaps);
}
/// <summary>
/// 寻找与指定区间有重叠的区间
/// </summary>
/// <param name="interval"></param>
/// <returns></returns>
public List <IIntervalable> GetOverlap(IIntervalable interval)
{
var overlaps = new List <IIntervalable>();
if (_point < interval.Start)
{
// 右边找找
AddOverlaps(interval, overlaps, FindOverlapRange(_right, interval));
AddOverlaps(interval, overlaps, Check4Overlap(interval, Direction.RIGHT));
}
else if (_point > interval.End) // 目标区间在当前节点的中点的左边
{
AddOverlaps(interval, overlaps, FindOverlapRange(_left, interval));
AddOverlaps(interval, overlaps, Check4Overlap(interval, Direction.LEFT));
}
else
{
AddOverlaps(interval, overlaps, _intervals);
AddOverlaps(interval, overlaps, FindOverlapRange(_left, interval));
AddOverlaps(interval, overlaps, FindOverlapRange(_right, interval));
}
return(overlaps);
}
public List <IIntervalable> FindOverlaps(IIntervalable interval) => _root.GetOverlap(interval);
