Data commit

Task/Modular-arithmetic/C-sharp/modular-arithmetic.cs

@@ -0,0 +1,86 @@
+using System;
+
+namespace ModularArithmetic {
+    interface IAddition<T> {
+        T Add(T rhs);
+    }
+    interface IMultiplication<T> {
+        T Multiply(T rhs);
+    }
+    interface IPower<T> {
+        T Power(int pow);
+    }
+    interface IOne<T> {
+        T One();
+    }
+
+    class ModInt : IAddition<ModInt>, IMultiplication<ModInt>, IPower<ModInt>, IOne<ModInt> {
+        private int modulo;
+
+        public ModInt(int value, int modulo) {
+            Value = value;
+            this.modulo = modulo;
+        }
+
+        public int Value { get; }
+
+        public ModInt One() {
+            return new ModInt(1, modulo);
+        }
+
+        public ModInt Add(ModInt rhs) {
+            return this + rhs;
+        }
+
+        public ModInt Multiply(ModInt rhs) {
+            return this * rhs;
+        }
+
+        public ModInt Power(int pow) {
+            return Pow(this, pow);
+        }
+
+        public override string ToString() {
+            return string.Format("ModInt({0}, {1})", Value, modulo);
+        }
+
+        public static ModInt operator +(ModInt lhs, ModInt rhs) {
+            if (lhs.modulo != rhs.modulo) {
+                throw new ArgumentException("Cannot add rings with different modulus");
+            }
+            return new ModInt((lhs.Value + rhs.Value) % lhs.modulo, lhs.modulo);
+        }
+
+        public static ModInt operator *(ModInt lhs, ModInt rhs) {
+            if (lhs.modulo != rhs.modulo) {
+                throw new ArgumentException("Cannot add rings with different modulus");
+            }
+            return new ModInt((lhs.Value * rhs.Value) % lhs.modulo, lhs.modulo);
+        }
+
+        public static ModInt Pow(ModInt self, int p) {
+            if (p < 0) {
+                throw new ArgumentException("p must be zero or greater");
+            }
+
+            int pp = p;
+            ModInt pwr = self.One();
+            while (pp-- > 0) {
+                pwr *= self;
+            }
+            return pwr;
+        }
+    }
+
+    class Program {
+        static T F<T>(T x) where T : IAddition<T>, IMultiplication<T>, IPower<T>, IOne<T> {
+            return x.Power(100).Add(x).Add(x.One());
+        }
+
+        static void Main(string[] args) {
+            ModInt x = new ModInt(10, 13);
+            ModInt y = F(x);
+            Console.WriteLine("x ^ 100 + x + 1 for x = {0} is {1}", x, y);
+        }
+    }
+}