Cosmetics

Author: cdrnet

src/Numerics/Combinatorics.cs

@@ -160,9 +160,7 @@ public static void SelectPermutationInplace<T>(T[] data, System.Random randomSou
             for (int i = data.Length - 1; i > 0; i--)
             {
                 int swapIndex = random.Next(i + 1);
-                T swap = data[i];
-                data[i] = data[swapIndex];
-                data[swapIndex] = swap;
+                (data[i], data[swapIndex]) = (data[swapIndex], data[i]);
             }
         }
 
@@ -372,30 +370,36 @@ public static BigInteger[] GenerateVariation(BigInteger n, int k, System.Random
             if (k > n) throw new ArgumentOutOfRangeException(nameof(k), $"k must be smaller than or equal to n.");
 
             var random = randomSource ?? SystemRandomSource.Default;
+
             BigInteger[] selection = new BigInteger[k];
             if (n == 0 || k == 0)
+            {
                 return selection;
-            selection[0] = random.NextBigIntegerSequence(0, n).First();
-            bool[] CompareCache;
-            bool KeepLooping;
-            BigInteger RandomNumber;
+            }
+
+            selection[0] = random.NextBigIntegerSequence(BigInteger.Zero, n).First();
+            bool[] compareCache;
+            bool keepLooping;
+            BigInteger randomNumber;
+
             for (int a = 1; a < k; a++)
             {
-                RandomNumber = random.NextBigIntegerSequence(0, n - a).First();
-                CompareCache = Enumerable.Repeat(true, a).ToArray();
+                randomNumber = random.NextBigIntegerSequence(BigInteger.Zero, n - a).First();
+                compareCache = Generate.Repeat(a, true);
                 do
                 {
-                    KeepLooping = false;
+                    keepLooping = false;
                     for (int b = 0; b < a; ++b)
-                        if (CompareCache[b] && RandomNumber >= selection[b])
+                        if (compareCache[b] && randomNumber >= selection[b])
                         {
-                            CompareCache[b] = false;
-                            KeepLooping = true;
-                            RandomNumber++;
+                            compareCache[b] = false;
+                            keepLooping = true;
+                            randomNumber++;
                         }
-                } while (KeepLooping);
-                selection[a] = RandomNumber;
+                } while (keepLooping);
+                selection[a] = randomNumber;
             }
+
             return selection;
         }
 

src/Numerics/Random/RandomExtensions.cs

@@ -202,22 +202,23 @@ static IEnumerable<int> NextInt32SequenceEnumerable(System.Random rnd, int minIn
         /// </remarks>
         public static IEnumerable<BigInteger> NextBigIntegerSequence(this System.Random rnd, BigInteger minInclusive, BigInteger maxExclusive)
         {
-            BigInteger AbsoluteRange = maxExclusive - minInclusive;
-            int NumBytes = (int)Math.Ceiling(BigInteger.Log(AbsoluteRange, byte.MaxValue) * 2) + 1;
-            byte[] ByteSequence = Enumerable.Repeat(byte.MaxValue, NumBytes + 1).ToArray();
-            ByteSequence[NumBytes] = 0;
-            BigInteger RandomNumber = new BigInteger(ByteSequence);
-            BigInteger ValidRange = RandomNumber - RandomNumber % AbsoluteRange;
+            BigInteger absoluteRange = maxExclusive - minInclusive;
+            int numBytes = (int)Math.Ceiling(BigInteger.Log(absoluteRange, byte.MaxValue) * 2) + 1;
+            byte[] byteSequence = Generate.Repeat(numBytes + 1, byte.MaxValue);
+            byteSequence[numBytes] = 0;
+            BigInteger randomNumber = new BigInteger(byteSequence);
+            BigInteger validRange = randomNumber - randomNumber % absoluteRange;
+
             while(true)
             {
                 do
                 {
-                    rnd.NextBytes(ByteSequence);
-                    ByteSequence[NumBytes] = 0;
-                    RandomNumber = new BigInteger(ByteSequence);
+                    rnd.NextBytes(byteSequence);
+                    byteSequence[numBytes] = 0;
+                    randomNumber = new BigInteger(byteSequence);
                 }
-                while (RandomNumber >= ValidRange);
-                yield return RandomNumber % AbsoluteRange + minInclusive;
+                while (randomNumber >= validRange);
+                yield return randomNumber % absoluteRange + minInclusive;
             }
         }