Sort list by string resemblance

Question

I have a list of string:

AAA
BBB
CCC
ABB
ABC
ACC
ACD

The user will type what he is looking for, would like to take to the first positions, the most similar. Example:

String: A

Upshot:

AAA
ABB
ABC
ACC
ACD
BBB
CCC

String: AB

Upshot:

ABB
ABC
AAA
ACC
ACD
BBB
CCC

String: C

Upshot:

CCC
AAA
ABB
ABC
ACC
ACD
BBB

String: AC

Upshot:

ACC
ACD
AAA
ABB
ABC
CCC
BBB

String: B

Upshot:

BBB
AAA
ABB
ABC
ACC
ACD
CCC

Edit:

Just incrementing the @Mario solution that worked perfectly:

lista.OrderByDescending(x => (x.StartsWith(padrao))).ThenByDescending(x => (x.Contains(padrao)));

And that way I got an even better result than expected.

Answer 1

What seems to have been defined as similar is whether the substring exists in the string of each element in the list. Then just sort the ones you have first, so the OrderByDecending() applied in the Contains(). It will group everything it contains and then what does not contain the text pattern.

using System;
using System.Collections.Generic;
using System.Linq;

public class Program {
    public static void Main() {
        var lista = new List<string> { "AAA", "BBB", "CCC", "ABB", "ABC", "ACC", "ACD" };
        Semelhante(lista, "A");
        Semelhante(lista, "B");
        Semelhante(lista, "C");
        Semelhante(lista, "AB");
        Semelhante(lista, "AC");
    }
    public static void Semelhante(List<string> lista, string padrao) {
        foreach (var item in lista.OrderByDescending(x => (x.Contains(padrao)))) {
            Console.WriteLine(item);
        }
        Console.WriteLine();
    }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.

In new edition in the question has an even better option, but only the AP knew that was what needed.

---

Previously I interpreted differently what was resemblance. Stay just to try to help someone else.

I think it can be improved and not fully tested. Alert Gambi to use only LINQ :P

The OrderBy() waits for the element that should be used to classify it, which should be the key. So I am sending him the amount of occurrences of the substring that he found as key, after all the more occurrences, the closer it is. I used the Count() in string to find the number of occurrences.

It may be that the requirement of "similar" was not quite that, but the question does not make it so clear. The result is as expected.

I don’t know if AAB is better than ABC because it has 2 Bs or if because B comes before C (mine got like this).

using System;
using System.Collections.Generic;
using System.Linq;

public class Program {
    public static void Main() {
        var lista = new List<string> { "AAA", "BBB", "CCC", "ABB", "ABC", "ACC", "ACD" };
        var padrao = "A";
        foreach (var item in lista.OrderByDescending(x => x.Select((c, i) => x.Substring(i)).Count(sub => sub.StartsWith(padrao)))) {
            Console.WriteLine(item);
        }
        Console.WriteLine();
        padrao = "AB";
        foreach (var item in lista.OrderByDescending(x => x.Select((c, i) => x.Substring(i)).Count(sub => sub.StartsWith(padrao)))) {
            Console.WriteLine(item);
        }
    }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.