How to convert a numeric array into a range?

Question

myArray: 1,2,3,5,6,8,9,7,10,20,21,23,22 at 10000 integer [but Unique]...

need convert to

1-3 and 5-10 and 20-22 ...

I have an array like this: myArray

I want it to be converted to range with the least iteration loop (for)..I can't write code in parallel..maybe parallel is the answer.

With the best technique for high speed

When it is in the filter is like this, the speed is very low.

MyDataTable.DefaultView.RowFilter = "[ID] in(1,2,4,5,6,8,7,9,10)" 'at 10000

And when the filter is like this, the speed is higher:

MyDataTable.DefaultView.RowFilter = "[ID] >=1AND [ID] <=4 OR [ID] >=6 AND [ID] <=12"

Thank.

tags: vb.net-vs2019-dataTable-DataGridView-Filter

Answer 1

Check this example:

Dim myArray As Integer() = {1, 2, 3, 5, 6, 8, 9, 7, 10, 20, 21, 23, 22}

Dim result As Integer()() = myArray _
    .OrderBy(Function(x) x) _
    .Select(Function(x, i) New With {x, i, .d = x - i}) _
    .GroupBy(Function(t) t.d) _
    .Select(Function(g) New Integer() {g.Min(Function(t) t.x), g.Max(Function(t) t.x)}) _
    .ToArray

It returns a bidimensional array; each row contains the range.