ekepes · January 8, 2022 05:00 · Dec 21, 2015
diff --git a/ConsoleApplication2.cs b/ConsoleApplication2.cs
@@ -0,0 +1,57 @@
+using System;
+
+namespace ConsoleApplication2
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            var freq = new int[20];
+            var rng = new RandomNumberGenerator();
+            for (int i = 0; i < 100; i++)
+            {
+                var rnd = rng.Next(20);
+                freq[rnd] += 1;
+                Console.Write("{0}, ", rnd);
+            }
+
+            Console.WriteLine("Done.");
+            for (int i = 0; i < 20; i++)
+            {
+                Console.Write("{0}={1}\t", i, freq[i]);
+            }
+            Console.ReadLine();
+        }
+    }
+
+    // Based on https://en.wikipedia.org/wiki/Linear_congruential_generator
+    class RandomNumberGenerator
+    {
+        private const long m = 4294967296; // aka 2^32
+        private const long a = 1664525;
+        private const long c = 1013904223;
+        private long _last;
+
+        public RandomNumberGenerator()
+        {
+            _last = DateTime.Now.Ticks % m;
+        }
+
+        public RandomNumberGenerator(long seed)
+        {
+            _last = seed;
+        }
+
+        public long Next()
+        {
+            _last = ((a * _last) + c) % m;
+
+            return _last;
+        }
+
+        public long Next(long maxValue)
+        {
+            return Next() % maxValue;
+        }
+    }
+}