Merge branch 'master' into fix/update-tests-for-timsort-and-hashtable

Author: siriak

Algorithms/Encoders/SoundexEncoder.cs

@@ -5,6 +5,36 @@ namespace Algorithms.Encoders;
 /// </summary>
 public class SoundexEncoder
 {
+    private static readonly Dictionary<char, int> CharacterMapping = new()
+    {
+        ['a'] = 0,
+        ['e'] = 0,
+        ['i'] = 0,
+        ['o'] = 0,
+        ['u'] = 0,
+        ['y'] = 0,
+        ['h'] = 8,
+        ['w'] = 8,
+        ['b'] = 1,
+        ['f'] = 1,
+        ['p'] = 1,
+        ['v'] = 1,
+        ['c'] = 2,
+        ['g'] = 2,
+        ['j'] = 2,
+        ['k'] = 2,
+        ['q'] = 2,
+        ['s'] = 2,
+        ['x'] = 2,
+        ['z'] = 2,
+        ['d'] = 3,
+        ['t'] = 3,
+        ['l'] = 4,
+        ['m'] = 5,
+        ['n'] = 5,
+        ['r'] = 6,
+    };
+
     /// <summary>
     ///     Encodes a string using the Soundex Algorithm.
     /// </summary>
@@ -72,36 +102,6 @@ private IEnumerable<int> CollapseDoubles(IEnumerable<int> numbers)
 
     private int MapToNumber(char ch)
     {
-        var mapping = new Dictionary<char, int>
-        {
-            ['a'] = 0,
-            ['e'] = 0,
-            ['i'] = 0,
-            ['o'] = 0,
-            ['u'] = 0,
-            ['y'] = 0,
-            ['h'] = 8,
-            ['w'] = 8,
-            ['b'] = 1,
-            ['f'] = 1,
-            ['p'] = 1,
-            ['v'] = 1,
-            ['c'] = 2,
-            ['g'] = 2,
-            ['j'] = 2,
-            ['k'] = 2,
-            ['q'] = 2,
-            ['s'] = 2,
-            ['x'] = 2,
-            ['z'] = 2,
-            ['d'] = 3,
-            ['t'] = 3,
-            ['l'] = 4,
-            ['m'] = 5,
-            ['n'] = 5,
-            ['r'] = 6,
-        };
-
-        return mapping[ch];
+        return CharacterMapping[ch];
     }
 }

Algorithms/Other/Luhn.cs

@@ -21,49 +21,49 @@ public static class Luhn
     public static bool Validate(string number) => GetSum(number) % 10 == 0;
 
     /// <summary>
-    ///     This algorithm only finds one number.
+    ///     This algorithm finds one missing digit.
     ///     In place of the unknown digit, put "x".
     /// </summary>
     /// <param name="number">The number in which to find the missing digit.</param>
     /// <returns>Missing digit.</returns>
     public static int GetLostNum(string number)
     {
-        var lostIndex = number.Length - 1 - number.LastIndexOf("x", StringComparison.CurrentCultureIgnoreCase);
-        var lostNum = GetSum(number.Replace("x", "0", StringComparison.CurrentCultureIgnoreCase)) * 9 % 10;
+        var missingDigitIndex = number.Length - 1 - number.LastIndexOf("x", StringComparison.CurrentCultureIgnoreCase);
+        var checkDigit = GetSum(number.Replace("x", "0", StringComparison.CurrentCultureIgnoreCase)) * 9 % 10;
 
-        // Case 1: If the index of the lost digit is even.
-        if (lostIndex % 2 == 0)
+        // Case 1: If the index of the missing digit is even.
+        if (missingDigitIndex % 2 == 0)
         {
-            return lostNum;
+            return checkDigit;
         }
 
-        var tempLostNum = lostNum / 2;
+        var candidateDigit = checkDigit / 2;
 
-        // Case 2: if the index of the lost digit isn`t even and that number <= 4.
-        // Case 3: if the index of the lost digit isn`t even and that number > 4.
-        return Validate(number.Replace("x", tempLostNum.ToString())) ? tempLostNum : (lostNum + 9) / 2;
+        // Case 2: if the index of the missing digit is odd and the candidate is valid.
+        // Case 3: if the index of the missing digit is odd and we need the alternative.
+        return Validate(number.Replace("x", candidateDigit.ToString())) ? candidateDigit : (checkDigit + 9) / 2;
     }
 
     /// <summary>
-    ///     Computes the sum found by the algorithm.
+    ///     Computes the sum found by the Luhn algorithm.
     /// </summary>
-    /// <param name="number">The number for which the sum will be found.</param>
+    /// <param name="number">The number for which the sum will be calculated.</param>
     /// <returns>Sum.</returns>
     private static int GetSum(string number)
     {
         var sum = 0;
         for (var i = 0; i < number.Length; i++)
         {
-            var d = number[i] - '0';
-            d = (i + number.Length) % 2 == 0
-                ? 2 * d
-                : d;
-            if (d > 9)
+            var digit = number[i] - '0';
+            digit = (i + number.Length) % 2 == 0
+                ? 2 * digit
+                : digit;
+            if (digit > 9)
             {
-                d -= 9;
+                digit -= 9;
             }
 
-            sum += d;
+            sum += digit;
         }
 
         return sum;

DataStructures.Tests/AATreeTests.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using DataStructures.AATree;
-using FluentAssertions;
-using NUnit.Framework;
 
 namespace DataStructures.Tests;
 

DataStructures.Tests/AVLTreeTests.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using DataStructures.AVLTree;
-using FluentAssertions;
-using NUnit.Framework;
 using static FluentAssertions.FluentActions;
 
 namespace DataStructures.Tests;
@@ -233,19 +228,19 @@ public void Remove_MultipleKeys_TreeStillValid_Variant2()
         tree.GetKeysInOrder()
             .Should()
             .BeEquivalentTo(
-                new[] { 4,6,8 },
+                new[] { 4, 6, 8 },
                 config => config.WithStrictOrdering());
 
         tree.GetKeysPreOrder()
             .Should()
             .BeEquivalentTo(
-                new[] { 6,4,8 },
+                new[] { 6, 4, 8 },
                 config => config.WithStrictOrdering());
 
         tree.GetKeysPostOrder()
             .Should()
             .BeEquivalentTo(
-                new[] { 4,8,6 },
+                new[] { 4, 8, 6 },
                 config => config.WithStrictOrdering());
     }
 

DataStructures.Tests/BinarySearchTreeTests.cs

@@ -1,8 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
 using DataStructures.BinarySearchTree;
-using NUnit.Framework;
 
 namespace DataStructures.Tests;
 

DataStructures.Tests/BitArrayTests.cs

@@ -1,7 +1,3 @@
-using System;
-using FluentAssertions;
-using NUnit.Framework;
-
 namespace DataStructures.Tests;
 
 /// <summary>

DataStructures.Tests/Cache/LfuCacheTests.cs

@@ -1,6 +1,4 @@
 using DataStructures.Cache;
-using FluentAssertions;
-using NUnit.Framework;
 
 namespace DataStructures.Tests.Cache;
 

DataStructures.Tests/Cache/LruCacheTests.cs

@@ -1,6 +1,4 @@
 using DataStructures.Cache;
-using FluentAssertions;
-using NUnit.Framework;
 
 namespace DataStructures.Tests.Cache;
 

DataStructures.Tests/DisjointSet/DisjointSetTests.cs

@@ -1,6 +1,4 @@
 using DataStructures.DisjointSet;
-using FluentAssertions;
-using NUnit.Framework;
 
 namespace DataStructures.Tests.DisjointSet;
 

DataStructures.Tests/Fenwick/BinaryIndexedTreeTests.cs

@@ -1,6 +1,4 @@
 using DataStructures.Fenwick;
-using FluentAssertions;
-using NUnit.Framework;
 
 namespace DataStructures.Tests.Fenwick;