CM2

using System;
using System.Collections.Generic;

namespace CM2
{
    class Program
    {
        private static double[] unkn = new double[3];
        private static double[] unknNull = new double[3];
        private static double[] coef =
        {
            1.667, 0.33, 0.5,
            - 0.6, 2.4, 0.3,
            - 0.33, 0.5, 2.5
        };

        static void Main(string[] args)
        {
            double eps = 0.001, eps1 = 0.00001;

            Console.WriteLine("Введите начальные приближения: ");
            for (int i = 0; i < 3; i++)
            {
                Console.WriteLine("x{0} = ", i);
                unknNull[i] = 0;
            }

            Console.WriteLine("Кол-во итераций: {0}", MZ(eps));

            for (int i = 0; i < unkn.Length; i++)
            {
                Console.WriteLine("x{0} = {1}", i, unkn[i]);
            }
        }

        static int RL(double eps)
        {
            int k = 0;

            for(k = 1;; k++)
            {
                for (int i = 0; i < unkn.Length; i++)
                {
                    for (int j = i * 3; j < (i + 1) * 3; j++)
                    {
                        unkn[i] += coef[j] * (j % 3 != i ? unknNull[j % 3] : 1);
                        //Console.WriteLine("unkn[{2}]={0}, unkn={6}, j = {1}, i ={2}, coef[{1}]={3}, unknNull[{4}]={5}", unkn[i], j, i, coef[j], j % 3, (j % 3 != i ? unknNull[j % 3] : 1), coef[j] * (j % 3 != i  ? unknNull[j % 3] : 1));
                    }
                }
                Console.WriteLine("x = {0}\ny = {1}\nz = {2}", unkn[0], unkn[1], unkn[2]);
                Console.WriteLine("x0 = {0}\ny0 = {1}\nz0 = {2}\nk = {3}", unknNull[0], unknNull[1], unknNull[2], k);

                if (Math.Abs(unkn[0] - unknNull[0]) + Math.Abs(unkn[1] - unknNull[1]) +
                    Math.Abs(unkn[2] - unknNull[2]) <= eps) break;

                unknNull = unkn;
                unkn = new double[unknNull.Length];
            }

            return k;
        }

        static int MZ(double eps)
        {
            int k = 0;

            for(k = 1;; k++)
            {
                for (int i = 0; i < unkn.Length; i++)
                {
                    for (int j = i * 3; j < (i + 1) * 3; j++)
                    {
                        unkn[i] += coef[j] * (j % 3 != i ? (i == 0 ? unknNull[j % 3] : i == 1 ? j % 3 == 0 ? unkn[i-1] : unknNull[j % 3] : i == 2 ? unkn[j % 3] : 1) : 1);
                        //Console.WriteLine("unkn[{2}]={0}, unkn={6}, j = {1}, i ={2}, coef[{1}]={3}, unknNull[{4}]={5}", unkn[i], j, i, coef[j], j % 3, (j % 3 != i ? unknNull[j % 3] : 1), coef[j] * (j % 3 != i  ? unknNull[j % 3] : 1));
                    }
                }
                Console.WriteLine("x = {0}\ny = {1}\nz = {2}", unkn[0], unkn[1], unkn[2]);
                Console.WriteLine("x0 = {0}\ny0 = {1}\nz0 = {2}\nk = {3}", unknNull[0], unknNull[1], unknNull[2], k);

                if (Math.Abs(unkn[0] - unknNull[0]) + Math.Abs(unkn[1] - unknNull[1]) +
                    Math.Abs(unkn[2] - unknNull[2]) <= eps) break;

                unknNull = unkn;
                unkn = new double[unknNull.Length];
            }

            return k;
        }

        static int MPI(double eps)
        {
            int k = 0;

            for(k = 1;; k++)
            {
                for (int i = 0; i < unkn.Length; i++)
                {
                    for (int j = i * 3; j < (i + 1) * 3; j++)
                    {
                        unkn[i] += coef[j] * (j % 3 != i ? unknNull[j % 3] : 1);
                        //Console.WriteLine("unkn[{2}]={0}, unkn={6}, j = {1}, i ={2}, coef[{1}]={3}, unknNull[{4}]={5}", unkn[i], j, i, coef[j], j % 3, (j % 3 != i ? unknNull[j % 3] : 1), coef[j] * (j % 3 != i  ? unknNull[j % 3] : 1));
                    }
                }
                Console.WriteLine("x = {0}\ny = {1}\nz = {2}", unkn[0], unkn[1], unkn[2]);
                Console.WriteLine("x0 = {0}\ny0 = {1}\nz0 = {2}\nk = {3}", unknNull[0], unknNull[1], unknNull[2], k);

                if (Math.Abs(unkn[0] - unknNull[0]) + Math.Abs(unkn[1] - unknNull[1]) +
                    Math.Abs(unkn[2] - unknNull[2]) <= eps) break;

                unknNull = unkn;
                unkn = new double[unknNull.Length];
            }

            return k;
        }
    }
}