Добавил алгоритм проверки сходства строк

Для поиска похожих ключей по значению ячейки используется алгоритм шинглов.

AsbCloudInfrastructure/Services/WellOperationImport/FileParser/StringSimilarity/CosineSimilarity.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+
+namespace AsbCloudInfrastructure.Services.WellOperationImport.FileParser.StringSimilarity;
+
+public class CosineSimilarity
+{
+    private const int DefaultK = 2;
+
+    protected int K { get; }
+
+    public CosineSimilarity(int k)
+    {
+        if (k <= 0)
+        {
+            throw new ArgumentOutOfRangeException(nameof(k), "k should be positive!");
+        }
+
+        K = k;
+    }
+
+    public CosineSimilarity() : this(DefaultK) { }
+
+    public double Similarity(IDictionary<string, int> profile1, IDictionary<string, int> profile2)
+        => DotProduct(profile1, profile2)
+           / (Norm(profile1) * Norm(profile2));
+    
+    public Dictionary<string, int> GetProfile(string s)
+    {
+        var shingles = new Dictionary<string, int>();
+        
+        if (string.IsNullOrWhiteSpace(s))
+            return shingles;
+
+        var cleanString = Stemming(s);
+
+        for (int i = 0; i < (cleanString.Length - K + 1); i++)
+        {
+            var shingle = cleanString.Substring(i, K);
+
+            if (shingles.TryGetValue(shingle, out var old))
+            {
+                shingles[shingle] = old + 1;
+            }
+            else
+            {
+                shingles[shingle] = 1;
+            }
+        }
+
+        return shingles;
+    }
+
+    private static string Stemming(string s)
+    {
+        var cleaned = Regex.Replace(s.ToLower(), "[^a-zа-я0-9]", "");
+        var words = cleaned.Split(' ');
+        var filteredWords = words.Where(word => word.Length > 1).ToArray();
+        return string.Concat(filteredWords);
+    }
+
+    private static double Norm(IDictionary<string, int> profile)
+    {
+        double agg = 0;
+
+        foreach (var entry in profile)
+        {
+            agg += 1.0 * entry.Value * entry.Value;
+        }
+
+        return Math.Sqrt(agg);
+    }
+
+    private static double DotProduct(IDictionary<string, int> profile1, IDictionary<string, int> profile2)
+    {
+        var smallProfile = profile2;
+        var largeProfile = profile1;
+
+        if (profile1.Count < profile2.Count)
+        {
+            smallProfile = profile1;
+            largeProfile = profile2;
+        }
+
+        double agg = 0;
+        foreach (var entry in smallProfile)
+        {
+            if (!largeProfile.TryGetValue(entry.Key, out var i)) 
+                continue;
+
+            agg += 1.0 * entry.Value * i;
+        }
+
+        return agg;
+    }
+}