public IList <IList <int> > GetSkyline(int[][] buildings)
{
var sortedList = new SortedList <int, IList <int> >();
foreach (var building in buildings)
{
if (!sortedList.ContainsKey(building[0]))
{
sortedList.Add(building[0], new List <int>());
}
sortedList[building[0]].Add(-building[2]);
if (!sortedList.ContainsKey(building[1]))
{
sortedList.Add(building[1], new List <int>());
}
sortedList[building[1]].Add(building[2]);
}
var result = new List <IList <int> >();
var heights = new MaxPriorityQueue();
foreach (var x in sortedList.Keys)
{
foreach (var height in sortedList[x])
{
if (height < 0)
{
heights.Insert(-height);
}
else
{
heights.Delete(height);
}
}
if (heights.Size() == 0)
{
result.Add(new List <int>()
{
x, 0
});
}
else
{
var height = heights.Max();
if (result.Count == 0 || result[result.Count - 1][1] != height)
{
result.Add(new List <int>()
{
x, height
});
}
}
}
return(result);
}
