```/* F03BN_A1W_F C++ Header Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
* Mark 27, 2019.
*/

#include <dco.hpp>
#include <nag.h>
#include <nagx04.h>
#include <stdio.h>
#include <string>
#include <iostream>
using namespace std;

int main(void)
{
int       exit_status = 0;
Integer   ifail = 0;

cout << "F03BN_A1W_F C++ Header Example Program Results\n\n";
// Skip heading in data file
string mystr;
getline (cin, mystr);

// Read problem size and number of right-hand-sides
Integer n;
cin >> n;

// Allocate arrays containing A and its factorized form, B
// and the solution X.
Complex           *ar=0;
Integer           *ipiv=0;
ipiv =  new Integer           [n];
ar   =  new Complex           [n*n];

// Read the matrix A, register and copy
double dr, di;
Complex dc;
for (int i = 0; i<n; ++i) {
for (int j = 0; j<n; ++j) {
cin >> dr >> di;
Integer k = i + j*n;
a_r[k] = dr;
a_i[k] = di;
a[k].real(a_r[k]);
a[k].imag(a_i[k]);
ar[k].re = dr;
ar[k].im = di;
}
}

// Print matrix A
cout << endl;
NagError  fail;
INIT_FAIL(fail);
x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
"  A",0,&fail);

// Create AD configuration data object
ifail = 0;

// Factorize the matrix A
ifail = 0;

// Print Factorization of A
for (int i = 0; i<n; i++) {
for (int j = 0; j<n; j++) {
int k = i + j*n;

akr = real(a[k]);
aki = imag(a[k]);
}
}
cout << endl;
// NagError  fail;
INIT_FAIL(fail);
x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
"  Array A after factorization",0,&fail);

Integer           id[2];
ifail = 0;

dcr = real(d);
dci = imag(d);
cout << " d = (" << dr << "," << di << ") id = ";
cout << id[0] << ", " << id[1] << endl;
dr = dr*pow(2.0,id[0]);
di = di*pow(2.0,id[1]);
cout << "\n value of determinant = (" << dr << "," << di << ")" << endl;

cout << "\n\n Derivatives calculated: First order adjoints\n";
cout << " Computational mode    : algorithmic\n";
cout << "\n Derivatives of real(d) w.r.t A:\n";

// Obtain derivatives
double inc = 1.0;
dt = real(d);
ifail = 0;

for (int i=0; i<n; i++) {
for (int j=0; j<n; j++) {
Integer k = i + j*n;
ar[k].re = dr;
ar[k].im = di;
}
}

// Print derivatives
cout << endl;
INIT_FAIL(fail);
x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
"           d(dreal)/da(i,j)",0,&fail);

END:
// Remove computational data object and tape
ifail = 0;