using System;

namespace single_dimension_vs_multidimension
{
    class Program
    {


        public static double sum(double[] d, int l1, int l2)
        {    // assuming the array is rectangular
            double sum = 0;
            int l3 = d.Length / (l1 * l2);
            for (int i = 0; i < l1; ++i)
                for (int j = 0; j < l2; ++j)
                    for (int k = 0; k < l3; ++k)
                        sum += d[i * l2 + j * l3 + k];
            return sum;
        }

        public static double sum(double[,,] d)
        {
            double sum = 0;
            int l1 = d.GetLength(0);
            int l2 = d.GetLength(1);
            int l3 = d.GetLength(2);
            for (int i = 0; i < l1; ++i)
                for (int j = 0; j < l2; ++j)
                    for (int k = 0; k < l3; ++k)
                        sum += d[i, j, k];
            return sum;
        }
        public static double sum(double[][][] d)
        {
            double sum = 0;
            for (int i = 0; i < d.Length; ++i)
                for (int j = 0; j < d[i].Length; ++j)
                    for (int k = 0; k < d[j].Length; ++k)
                        sum += d[i][j][k];
            return sum;
        }
        public static void TestTime<T, TR>(Func<T, TR> action, T obj, int iterations)
        {
            Stopwatch stopwatch = Stopwatch.StartNew();
            for (int i = 0; i < iterations; ++i)
                action(obj);
            Console.WriteLine(action.Method.Name + " took " + stopwatch.Elapsed);
        }
        public static void TestTime<T1, T2, T3, TR>(Func<T1, T2, T3, TR> action, T1 obj1, T2 obj2, T3 obj3, int iterations)
        {
            Stopwatch stopwatch = Stopwatch.StartNew();
            for (int i = 0; i < iterations; ++i)
                action(obj1, obj2, obj3);
            Console.WriteLine(action.Method.Name + " took " + stopwatch.Elapsed);
        }
        public static void Main()
        {
            Random random = new Random();
            const int l1 = 256, l2 = 256, l3 = 256;
            double[] d1 = new double[l1 * l2 * l3];
            double[,,] d2 = new double[l1, l2, l3];
            double[][][] d3 = new double[l1][][];
            for (int i = 0; i < l1; ++i)
            {
                d3[i] = new double[l2][];
                for (int j = 0; j < l2; ++j)
                {
                    d3[i][j] = new double[l3];
                    for (int k = 0; k < l3; ++k)
                        d3[i][j][k] = d2[i, j, k] = d1[i * l2 + j * l3 + k] = random.NextDouble();
                }
            }
            const int iterations = 1000;
            TestTime<double[], int, int, double>(sum, d1, l1, l2, iterations);
            TestTime<double[,,], double>(sum, d2, iterations);
            TestTime<double[][][], double>(sum, d3, iterations);

            TestTime<double[], int, int, double>(sum, d1, l1, l2, iterations);
            TestTime<double[,,], double>(sum, d2, iterations);
            TestTime<double[][][], double>(sum, d3, iterations);
        }

    }
}