static int Compare(NumberRange left, NumberRange right)
{
if (left.Start == right.Start)
{
return(left.End.CompareTo(right.End));
}
return(left.Start.CompareTo(right.Start));
}
/// <summary>
/// Merges any overlapping and contigious ranges
/// </summary>
public static ICollection <NumberRange> MergeOverlapping(this IList <NumberRange> ranges)
{
if (ranges.Count == 0)
{
return(ranges);
}
var arr = ranges.ToArray();
Array.Sort(arr, Compare);
var stack = new Stack <NumberRange>();
stack.Push(arr[0]);
for (var i = 0; i < arr.Length; i++)
{
var top = stack.Peek();
// If the current intervals end is just after our current. Merge
if (top.End + 1 == arr[i].Start)
{
var next = new NumberRange(top.Start, arr[i].End);
stack.Pop();
stack.Push(next);
}
// if current interval is not overlapping with stack top,
// Push it to the stack
else if (top.End < arr[i].Start)
{
stack.Push(arr[i]);
}
else if (top.End < arr[i].End)
{
var next = new NumberRange(top.Start, arr[i].End);
stack.Pop();
stack.Push(next);
}
}
return(stack.Reverse().ToArray());