Task: Kronecker product



C#: using System;
using System.Collections;
using System.Collections.Generic;
using static System.Linq.Enumerable;

public static class KroneckerProduct
{
    public static void Main() {
        int[,] left = { {1, 2}, {3, 4} };
        int[,] right = { {0, 5}, {6, 7} };
        Print(Multiply(left, right));

        left = new [,] { {0, 1, 0}, {1, 1, 1}, {0, 1, 0} };
        right = new [,] { {1, 1, 1, 1}, {1, 0, 0, 1}, {1, 1, 1, 1} };
        Print(Multiply(left, right));
    }

    static int[,] Multiply(int[,] left, int[,] right) {
        (int lRows, int lColumns) = (left.GetLength(0), left.GetLength(1));
        (int rRows, int rColumns) = (right.GetLength(0), right.GetLength(1));
        int[,] result = new int[lRows * rRows, lColumns * rColumns];

        foreach (var (r, c) in from r in Range(0, lRows) from c in Range(0, lColumns) select (r, c)) {
            Copy(r * rRows, c * rColumns, left[r, c]);
        }
        return result;
        
        void Copy(int startRow, int startColumn, int multiplier) {
            foreach (var (r, c) in from r in Range(0, rRows) from c in Range(0, rColumns) select (r, c)) {
                result[startRow + r, startColumn + c] = right[r, c] * multiplier;
            }
        }
    }

    static void Print(int[,] matrix) {
        (int rows, int columns) = (matrix.GetLength(0), matrix.GetLength(1));
        int width = matrix.Cast<int>().Select(LengthOf).Max();
        for (int row = 0; row < rows; row++) {
            Console.WriteLine("| " + string.Join(" ", Range(0, columns).Select(column => (matrix[row, column] + "").PadLeft(width, ' '))) + " |");
        }
        Console.WriteLine();
    }

    private static int LengthOf(int i) {
        if (i < 0) return LengthOf(-i) + 1;
        int length = 0;
        while (i > 0) {
            length++;
            i /= 10;
        }
        return length;
    }

}






VB: 
dim a(),b(),r()
 
sub kroneckerproduct 
    m=ubound(a,1): n=ubound(a,2)
    p=ubound(b,1): q=ubound(b,2)
    rtn=m*p
    ctn=n*q
    redim r(rtn,ctn) 
    for i=1 to m
        for j=1 to n
            for k=1 to p
                for l=1 to q
                    r(p*(i-1)+k,q*(j-1)+l)=a(i,j)*b(k,l)  
    next: next: next: next
end sub 
 
sub printmatrix(text,m,w)
    wscript.stdout.writeline text
    select case m
        case "a": ni=ubound(a,1): nj=ubound(a,2)
        case "b": ni=ubound(b,1): nj=ubound(b,2)
        case "r": ni=ubound(r,1): nj=ubound(r,2)
    end select
    for i=1 to ni
        for j=1 to nj
            select case m
                case "a": k=a(i,j)
                case "b": k=b(i,j)
                case "r": k=r(i,j)
            end select
            wscript.stdout.write right(space(w)&k,w)
        next
        wscript.stdout.writeline
    next
end sub 
 
sub printall(w)
    printmatrix "matrix a:", "a", w 
    printmatrix "matrix b:", "b", w 
    printmatrix "kronecker product:", "r", w  
end sub 
 
sub main()
    xa=array( 1, 2, _
              3, 4)
    redim a(2,2)
    k=0: for i=1 to ubound(a,1): for j=1 to ubound(a,1)
        a(i,j)=xa(k): k=k+1
    next:next
    xb=array( 0, 5, _ 
              6, 7)
    redim b(2,2)
    k=0: for i=1 to ubound(b,1): for j=1 to ubound(b,1)
        b(i,j)=xb(k): k=k+1
    next:next
    kroneckerproduct
    printall 3
 
    xa=array( 0, 1, 0, _ 
              1, 1, 1, _ 
              0, 1, 0)
    redim a(3,3)
    k=0: for i=1 to ubound(a,1): for j=1 to ubound(a,1)
        a(i,j)=xa(k): k=k+1
    next:next
    xb=array( 1, 1, 1, 1, _ 
              1, 0, 0, 1, _ 
              1, 1, 1, 1) 
    redim b(3,4)
    k=0: for i=1 to ubound(b,1): for j=1 to ubound(b,1)
        b(i,j)=xb(k): k=k+1
    next:next
    kroneckerproduct
    printall 2
end sub 

main