score:1
now that this has been clarified, the question is basically this:
- combine all elements from list a and list b, and if there are any duplicates, keep the one with the newest
lastgameplayed
.
i would do this with a grouping:
var players = from p in lista.concat(listb)
group p by p.id into g
select g.orderbydescending(x => x.lastgameplayed).first();
if performance is an issue, there are "faster" ways to write this, but i would start with this.
score:0
you can write an o(n log n) solution by building a set from list2 then overwriting (or inserting) items with list1, then converting that set back to a list.
if the lists are already sorted, you could do it o(n) by merging by hand.
score:2
you should be able to use the linq enumerable extension concat and exept to achieve this.
lista.concat(listb.except(lista);
this will remove items in b that match a, and them add the result to a.
you will have to write an iequalitycomparer which compares by id.
documentation for theses methods can be found here:
iequalitycomparer documentation can be found here:
Source: stackoverflow.com
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