I need more comparisons!

Author: ythosa

csharp/Platform.Numbers.Benchmarks/MathBenchmarks.cs

@@ -6,7 +6,7 @@ namespace Platform.Numbers.Benchmarks
     [MemoryDiagnoser]
     public class MathBenchmarks
     {
-        private const int FACTORIALTESTNUMBER = 10000;
+        private const int FACTORIALTESTNUMBER = 19;
 
         [Benchmark]
         public long FactorialUsingRecursion()
@@ -21,9 +21,15 @@ public long FactorialUsingFactTree()
         }
 
         [Benchmark]
-        public long FactorialUsingRecursionWihoutStaticField()
+        public long FactorialRecursionCountingArraylength()
         {
-            return Math.FactorialStatic(FACTORIALTESTNUMBER);
+            return Math.FactorialRecursionCountingArraylength(FACTORIALTESTNUMBER);
+        }
+
+        [Benchmark]
+        public long FactorialWhileWithArray()
+        {
+            return Math.FactorialWhileWithArray(FACTORIALTESTNUMBER);
         }
     }
 }

csharp/Platform.Numbers/Math.cs

@@ -43,13 +43,6 @@ public static class Math
         /// <returns><para>Result of factorial calculation.</para><para>Результат подсчета факториала</para></returns>
         public static long Factorial(long n)
         {
-            long[] _facts =
-            {
-                1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800,
-                479001600, 6227020800, 87178291200, 1307674368000, 20922789888000,
-                355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000,
-            };
-
             if (n <= 1)
             {
                 return 1;
@@ -58,7 +51,7 @@ public static long Factorial(long n)
 
             if (n < 21)
             {
-                return _facts[n];
+                return _factorials[n];
             }
 
             return n * Factorial(n - 1);
@@ -70,7 +63,7 @@ public static long Factorial(long n)
         /// </summary>
         /// <param name="n"><para>Factorial generation value.</para><para>Значение генерации факториала.</para></param>
         /// <returns><para>Result of factorial calculation.</para><para>Результат подсчета факториала</para></returns>
-        public static long FactorialStatic(long n)
+        public static long FactorialRecursionCountingArraylength(long n)
         {
             if (n <= 1)
             {
@@ -123,6 +116,21 @@ public static long FactTree(int n)
             return n * Factorial(n - 1);
         }
 
+        public static long FactorialWhileWithArray(long n)
+        {
+            long[] _facts =
+            {
+                1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800,
+                479001600, 6227020800, 87178291200, 1307674368000, 20922789888000,
+                355687428096000, 6402373705728000, 121645100408832000, 2432902008176640000,
+            };
+            if (n < _facts.Length) return _facts[n];
+
+            long r = n;
+            while (n > 1) r *= --n;
+            return r;
+        }
+
         /// <summary>
         /// <para>Generating the Catalan Number of the value "n".</para>
         /// <para>Генерация числа Каталана из значения переменной "n".</para>