Program.cs

using System;
using System.Collections.Generic;
namespace Matrix;

public class NumMatrix : object
{
	public readonly List<double[]> Rows = new();
	public int rows;
	public int columns;
    public static NumMatrix operator +(NumMatrix a, NumMatrix b) => MAdd(a, b);
    public static NumMatrix operator +(NumMatrix a, double b) => ScaleA(a, b);
    public static NumMatrix operator -(NumMatrix a, NumMatrix b) => MSub(a, b);
    public static NumMatrix operator *(NumMatrix a, double b) => ScaleM(a, b);
    public static NumMatrix operator -(NumMatrix a, double b) => ScaleS(a, b);
	public static NumMatrix operator /(NumMatrix a, double b) => ScaleD(a, b);
    public static NumMatrix operator +(double b, NumMatrix a) => ScaleA(a, b);
    public static NumMatrix operator *(double b, NumMatrix a) => ScaleM(a, b);
    public static NumMatrix operator -(double b, NumMatrix a) => ScaleS(a, b);
    public static NumMatrix operator /(double b, NumMatrix a) => ScaleD(a, b);
    public NumMatrix(int row, int col)
	{
		rows = row;
		columns = col;

		for (int i = 1; i <= rows; i++)  
		{
			double[] temp1;
			List<double> temp2 = new();
			for (int b = 1; b <= columns; b++)
			{
				temp2.Add(0);
			}
			temp1 = temp2.ToArray();
            Rows.Add(temp1);
        }
    }
	public double this[int row, int col]
	{ 
		get => Rows[row - 1][col - 1];
		set => Rows[row - 1][col - 1] = value;
	}

    public override string ToString()
    {
        var sb = new System.Text.StringBuilder();
        foreach (var row in Rows)
        {
            sb.Append('[').Append(string.Join(", ", row)).AppendLine("]");
        }
        return sb.ToString();
    }


    public int Items
	{
		get
		{
			return columns * rows;
		}

	}

	public NumMatrix MClear
	{
        get
        {
            return new NumMatrix(rows, columns);
        }
    }

    public void Clear()
    {
        for (int i = 0; i < rows; i++)
        {
            for (int j = 0; j < columns; j++)
            {
                Rows[i][j] = 0;
            }
        }
    }

    public static NumMatrix MAdd(NumMatrix a, NumMatrix b)
	{
		if (a.rows == b.rows)
		{
		}
		else throw new SizeException($"NumMatrix sizes uneven: {a.rows}x{a.columns} and {b.rows}x{b.columns}!");
		if (a.columns == b.columns)
		{
		}
		else throw new SizeException($"NumMatrix sizes uneven: {a.rows}x{a.columns} and {b.rows}x{b.columns}!");
		NumMatrix New = new NumMatrix(a.rows, a.columns);
		for (int i = 1; i <= New.rows; i++)
		{
			for (int i2 = 1; i2 <= New.columns; i2++)
			{
				New[i, i2] = a[i, i2] + b[i, i2];
			}
		}
		return New;

	}
	public static NumMatrix MSub(NumMatrix a, NumMatrix b)
	{
		if (a.rows == b.rows)
		{
		}
		else throw new SizeException($"NumMatrix sizes uneven: {a.rows}x{a.columns} and {b.rows}x{b.columns}!");
		if (a.columns == b.columns)
		{
		}
		else throw new SizeException($"NumMatrix sizes uneven: {a.rows}x{a.columns} and {b.rows}x{b.columns}!");
		NumMatrix New = new NumMatrix(a.rows, a.columns);
		for (int i = 1; i <= New.rows; i++)
		{
			for (int i2 = 1; i2 <= New.columns; i2++)
			{
				New[i, i2] = a[i, i2] - b[i, i2];
			}
		}
		return New;

	}
	public static NumMatrix ScaleA(NumMatrix ob, double scale)
	{
		NumMatrix Scaled = new(ob.rows, ob.columns);
		for (int i = 1; i <= Scaled.rows; i++)
		{
			for (int i2 = 1; i2 <= Scaled.columns; i2++)
			{
				Scaled[i, i2] = ob[i, i2] + scale;
			}
		}
		return Scaled;

	}
	public static NumMatrix ScaleS(NumMatrix ob, double scale)
	{
		NumMatrix Scaled = new(ob.rows, ob.columns);
		for (int i = 1; i <= Scaled.rows; i++)
		{
			for (int i2 = 1; i2 <= Scaled.columns; i2++)
			{
				Scaled[i, i2] = ob[i, i2] - scale;
			}
		}
		return Scaled;

	}
	public static NumMatrix ScaleM(NumMatrix ob, double scale)
	{
		NumMatrix Scaled = new(ob.rows, ob.columns);
		for (int i = 1; i <= Scaled.rows; i++)
		{
			for (int i2 = 1; i2 <= Scaled.columns; i2++)
			{
				Scaled[i, i2] = ob[i, i2] * scale;
			}
		}
		return Scaled;

	}

    public string Ssize
    {
        get
        {
            return $"{rows}x{columns}";
        }

    }
    public static NumMatrix ScaleD(NumMatrix ob, double scale)
	{
		NumMatrix Scaled = new(ob.rows, ob.columns);
		for (int i = 1; i <= Scaled.rows; i++)
		{
			for (int i2 = 1; i2 <= Scaled.columns; i2++)
			{
				Scaled[i, i2] = ob[i, i2] / scale;
			}
		}
		return Scaled;

	}
	public class SizeException : Exception
	{
		public SizeException(string message) : base(message) { }
	}
}

public class StringMatrix : object
{
    public readonly List<string[]> Rows = new();
    public int rows;
    public int columns;
    public StringMatrix(int row, int col)
    {
        rows = row;
        columns = col;

        for (int i = 1; i <= rows; i++)
        {
            string[] temp1;
            List<string> temp2 = new();
            for (int b = 1; b <= columns; b++)
            {
                temp2.Add(" ");
            }
            temp1 = temp2.ToArray();
            Rows.Add(temp1);
        }
    }
    public string this[int row, int col]
    {
        get => Rows[row - 1][col - 1];
        set => Rows[row - 1][col - 1] = value;
    }

    public override string ToString()
    {
        var sb = new System.Text.StringBuilder();
        foreach (var row in Rows)
        {
            sb.Append('[').Append(string.Join(", ", row)).AppendLine("]");
        }
        return sb.ToString();
    }

    public int Items
    {
        get
        {
            return columns * rows;
        }

    }
	public string Ssize
	{
		get
		{
			return $"{rows}x{columns}";
        }
	
	}

    public StringMatrix MClear
    {
        get
        {
            return new StringMatrix(rows, columns);
        }
    }

    public void Clear()
    {
        for (int i = 0; i < rows; i++)
        {
            for (int j = 0; j < columns; j++)
            {
                Rows[i][j] = " ";
            }
        }
    }

    public class SizeException : Exception
    {
        public SizeException(string message) : base(message) { }
    }
}