// A program that returns the determinant of a 3x3 matrix.
#include <iostream>
using namespace std;

double det_order3(double arg[3][3]) 
{
  double return_value =0.0 ;
 for (int n=0; n<3; ++n)
	{
	for (int m = 0 ; m < 3 ; ++m )
    return_value += std::pow(-1,n)*arg[0][n]*
	det_order2({{arg[n+1][]},{}}) ;
	}//
   return return_value ;
}



double det_order2(double arg[2][2]) 
{
  double return_value =0.0 ;
 for (int n=0; n<2; ++n)
    return_value = arg[0][0]*arg[1][1] - arg[1][0]*arg[0][1];
   return return_value ;
}

int main ()
{
  double A[3][3] = {{5, 10, 0 },{2, 4, -0.5}, {-1 2 3}};
 
cout << "The determinant of the matrix is = " <<det_order3(A) <<endl;

 return 0;
}