Minor code cleanup + microoptimization + readme update

README.md

@@ -28,7 +28,7 @@ Multi-threaded performance with RyuJIT (.NET 4.6, 64-bit system) on quad-core Sa
 
 * If phrases of 6 words are allowed as well, then "more difficult" hash is solved in 30 seconds, "easiest" in 3 minutes, and "hard" in 6 minutes.
 
-* If phrases of 7 words are allowed as well, then "more difficult" hash is solved in 6 minutes.
+* If phrases of 7 words are allowed as well, then "more difficult" hash is solved in 3 minutes.
 
 Note that all measurements were done on a Release build; Debug build is significantly slower.
 

WhiteRabbit/PermutationsGenerator.cs

@@ -8,7 +8,7 @@
     /// <summary>
     /// Code taken from https://ericlippert.com/2013/04/22/producing-permutations-part-three/
     /// </summary>
-    internal class PermutationsGenerator
+    internal sealed class PermutationsGenerator
     {
         public static IEnumerable<Permutation> HamiltonianPermutations(int n)
         {

WhiteRabbit/StringsProcessor.cs

@@ -6,7 +6,7 @@
     using System.Linq;
     using System.Numerics;
 
-    internal class StringsProcessor
+    internal sealed class StringsProcessor
     {
         public StringsProcessor(byte[] sourceString, int maxWordsCount, IEnumerable<byte[]> words)
         {

WhiteRabbit/VectorsConverter.cs

@@ -9,7 +9,7 @@
     /// Converts strings to vectors containing chars count, based on a source string.
     /// E.g. for source string "abc", string "a" is converted to [1, 0, 0], while string "bcb" is converted to [0, 2, 1].
     /// </summary>
-    internal class VectorsConverter
+    internal sealed class VectorsConverter
     {
         public VectorsConverter(byte[] sourceString)
         {

WhiteRabbit/VectorsProcessor.cs

@@ -7,7 +7,7 @@
     using System.Linq;
     using System.Numerics;
 
-    internal class VectorsProcessor
+    internal sealed class VectorsProcessor
     {
         private const byte MaxComponentValue = 8;
         private const int LeastCommonMultiple = 840;