private IEnumerable<Point> GetSkyLine(IEnumerable<Building> buildings)
{
var buildingsArray = buildings.ToArray();
var leftPoints = new Queue<Point>(buildingsArray.Select(item => new Point(item.Left, item.Height)));
var rightPoints = new Queue<Point>(buildingsArray.Select(item => new Point(item.Right, item.Height)).OrderBy(item => item.X));
var heights = new MaxHeap<int>(int.MinValue);
heights.Insert(0);
int height = 0;
while (leftPoints.Count != 0 || rightPoints.Count != 0)
{
bool takeLeftPoint = leftPoints.Count != 0 && leftPoints.Peek().X < rightPoints.Peek().X;
int x;
if (takeLeftPoint)
{
Point point = leftPoints.Dequeue();
x = point.X;
heights.Insert(point.Y);
}
else
{
Point point = rightPoints.Dequeue();
x = point.X;
heights.Remove(point.Y);
}
int maxHeight = heights.Maximum();
if (maxHeight != height)
{
height = maxHeight;
yield return new Point(x, height);
}
}
}
