```/* F01FJ_A1W_F C++ Header Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
* Mark 27, 2019.
*/

#include <dco_light.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 << "F01FJ_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           *ac=0;

ac   =  new Complex           [n*n];

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

// Create AD configuration data object
ifail = 0;

// Find log(A)
ifail = 0;

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

}
}

cout << endl;
NagError  fail;
INIT_FAIL(fail);
x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ac,n,
"  Log(A)",0,&fail);

cout << "\n\n Derivatives calculated: First order adjoints\n";
cout << " Computational mode    : algorithmic\n";
cout << "\n Derivatives of diagional of log(A) w.r.t diagonal of imag(A):\n";

// Obtain derivatives
for (int i=0; i<n; i++) {
double  inc = 1.0;
Integer k = i*n+i;
avr = real(a[k]);

ifail = 0;

for (int j=0; j<n; j++) {
Integer l = j + j*n, p = i + j*n;
ac[p].re = dd;
}

avi = imag(a[k]);

ifail = 0;

for (int j=0; j<n; j++) {
Integer l = j + j*n, p = i + j*n;
ac[p].im = dd;
}
}

// Print derivatives
cout << endl;
INIT_FAIL(fail);
x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ac,n,
"     d(logA(i,i)/dImag(A(j,j))",0,&fail);

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