Question

Using C# in .Net 2.0

When someone joins my server, I want to add their name, and the DateTime that they joined to a list/dictionary, as well as their score, which gets updated frequently.

I then want to be able to sort that list/dictionary by the DateTime or score, based on a boolean value, so that I can return the top 50% of the list/dictionary. i.e. return the names of the top 50% longest time between join and now, or the top 50% scores.

I’ve attempted it using two separate dictionaries, then using a custom sort by value method, but it’s messy, and doesn’t seem to work.

Is there an elegant way of doing this?

Answer 1

You could create a class to represent each user:

class User {
    public string Name { get; set; }
    public DateTime DateJoined { get; set; }
    public int Score { get; set; }
}

Then if you have a list of users

List<User> users = new List<User>();

you could sort it by score:

users.Sort(delegate (string left, string right) { 
    return left.Score.CompareTo(right.Score); 
});

or by date joined:

users.Sort(delegate (string left, string right) { 
    return left.DateJoined.CompareTo(right.DateJoined); 
});

If you can use C# 3 or later then this gets a lot nicer with Linq and Lambda expressions.

For example:

var top50pcUsersByScore = users.OrderBy(u => u.Score).Take(users.Count / 2);