using System using System Collections Generic using System Linq using

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace L1
{
    class Relaxation
    {
        Matrix mMatrix;
        Matrix b;
        int numIter = 0;

        public Relaxation(Matrix matrix, Matrix b)
        {
            this.mMatrix = matrix;
            this.b = b;
        }

        public double[] getSolve(double omega, double eps)
        {
            Matrix R = getMatrixR(mMatrix),
                   L = getMatrixL(mMatrix),
                   D = getMatrixD(mMatrix);
            Matrix Q1 = (D + omega * L).GetInverse() * ((1 - omega) * D - omega * R);

            R = getMatrixR(mMatrix);
            L = getMatrixL(mMatrix);
            D = getMatrixD(mMatrix);
            Matrix Q2 = omega * (D + omega * L).GetInverse() * b;
            Matrix curX = new Matrix(b), nextX = new Matrix(mMatrix.GetLength(0), 1);
            while (Math.Abs((nextX - curX).GetNorm()) >= eps)
            {
                ++numIter;
                curX = nextX;
                nextX = Q1 * curX + Q2;
            }
            return nextX.GetColumnArray(0, 0);
        }

        private Matrix getMatrixL(Matrix original)
        {
            Matrix matrix = new Matrix(original);
            for (int i = 0; i < matrix.GetLength(0); ++i)
            {
                for (int j = 0; j < matrix.GetLength(1); ++j)
                {
                    if (i <= j)
                    {
                        matrix[i, j] = 0;
                    }
                }
            }

            return matrix;
        }

        private Matrix getMatrixR(Matrix original)
        {
            Matrix matrix = new Matrix(original);
            for (int i = 0; i < matrix.GetLength(0); ++i)
            {
                for (int j = 0; j < matrix.GetLength(1); ++j)
                {
                    if (i >= j)
                    {
                        matrix[i, j] = 0;
                    }
                }
            }

            return matrix;
        }

        private Matrix getMatrixD(Matrix original)
        {
            Matrix matrix = new Matrix(original);
            for (int i = 0; i < matrix.GetLength(0); ++i)
            {
                for (int j = 0; j < matrix.GetLength(1); ++j)
                {
                    if (i != j)
                    {
                        matrix[i, j] = 0;
                    }
                }
            }

            return matrix;
        }

        public int getNumIter()
        {
            return numIter;
        }

        public bool isValid()
        {
            for (int i = 0; i < mMatrix.GetLength(0); ++i)
            {
                double maxValue = -100;
                int ind = 0;
                for (int j = 0; j < mMatrix.GetLength(1); ++j)
                {
                    if (mMatrix[i, j] > maxValue)
                    {
                        maxValue = mMatrix[i, j];
                        ind = j;
                    }
                }
                if (ind != i)
                    return false;
            }
            return true;

        }
    }
}