How to separate all consecutive Objects using Linq (C#)

Question

I have a List ... MyObject has a propert called LineId (integer)...

So, I need separate all consecutive LineId in List

Answer 1

A slightly smaller solution, but probably (read: definitely) less clear:

var lst = new [] {
    new { LineID = 1 },
    new { LineID = 1 },
    new { LineID = 1 },
    new { LineID = 2 },
    new { LineID = 1 },
    new { LineID = 2 },
};

var q = lst
    .Select((x,i) => new {Item = x, Index = i})
    .GroupBy(x => x.Item)
    .SelectMany(x => x.Select((y,i) => new { Item = y.Item, Index = y.Index, Sort = i - y.Index }))
    .OrderBy(x => x.Index)
    .GroupBy(x => x.Sort)
    .Select(x => x.Select(y => y.Item));

Returns an IEnumerable> :

1,1,1
2
1
2

Note, if you don't care about order, you can remove the 'OrderBy' line and the 'Index = y.Index' property in the anonymous object and it will return:

1,1,1
1
2
2