using System;
using System.Runtime.InteropServices;/* Provides mappings between C# and native code */

namespace NumericalAlgorithmsGroup
{
  class LUSolve
    {
      [DllImport("FLDLL214Z_nag.dll")]/* Import from DLL, the C# compiler provides a rudimentry check of the signature */
	public static extern void F04AJF(ref int n, ref int ir, double [,] a, ref int ia, double [] p, double [,] b,
					 ref int ib);
      [DllImport("FLDLL214Z_nag.dll")]
	public static extern void F03AFF(ref int n, ref double eps, double [,] a, ref int ia, ref double d1, ref int id,
					 double [] p, ref int ifail);

      public static void Main()
	{
	  double [,] a = {
	    {33, 16, 72},
	    {-24, -10, -57},
	    {-8, -4, -17}
	  };

	  double [,] b = {{-359, -359},{ 281, 281}, {85,85}};
	  int n = a.GetLength(0);
	  int ir = b.GetLength(1);
	  double eps = 1.0e-16;
	  double d1=0.0;
	  int id=0;
	  double [] p = new double [n];
	  int ifail=1;
	  double [,] at = new double [n,n];
	  for (int i=0; i<n;i++)
	    {
	      for (int j=0; j<n; j++)
		{
		  at[j,i] = a[i,j]; /* Transpose */
		}
	    }
	  F03AFF(ref n, ref eps, at, ref n, ref d1, ref id, p, ref ifail);
	  double [,] bt = new double [ir,n];
	  for (int i=0; i<n;i++)
	    {
	      for (int j=0; j<ir; j++)
		{
		  bt[j,i] = b[i,j];/* Transpose */
		}
	    }
	  F04AJF(ref n, ref ir, at, ref n, p, bt, ref n);
	  Console.WriteLine("Solution\n");
	  for (int i=0; i<n;i++)
	    {
	      for (int j=0; j<ir; j++)
		{
		  Console.Write("{0, 8:F4}", bt[j,i]);/* transposed array being output */
		}
	      Console.WriteLine("");
	    }
       	
	}
    }
}