Convert List to List> using Linq [duplicate]

Answer 1

You can use LINQ Aggregate() function (the code is longer than a simple loop):

var result = 
input.Aggregate(new List>(),
                (acc, s) =>
                {
                    if (acc.Count == 0 || acc[acc.Count - 1].Count == 2)
                        acc.Add(new List(2) { s });
                    else
                        acc[acc.Count - 1].Add(s);
                    return acc;
                })
                .Select(x => new KeyValuePair(x[0], x[1]))
                .ToList();

N.B.
this works even if your initial input becomes a generic IEnumerable and not specifically a List