```/* F07AA_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;
void      *ad_handle = 0;
Integer   ifail = 0;

cout << "F07AA_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, nrhs;
cin >> n >> nrhs;

// Allocate arrays containing A and its factorized form, B
// and the solution X.
nagad_a1w_w_rtype *a=0, *a_in=0, *b=0, *b_in=0;
double            *ar=0, *br=0;
Integer           *ipiv=0;
a    = new nagad_a1w_w_rtype [n*n];
a_in = new nagad_a1w_w_rtype [n*n];
b    = new nagad_a1w_w_rtype [n*nrhs];
b_in = new nagad_a1w_w_rtype [n*nrhs];
ipiv = new Integer [n];
ar   = new double [n*n];
br   = new double [n*nrhs];

// Create AD tape

// Read the matrix A and copy
double dd;
for (int i = 0; i<n; ++i) {
for (int j = 0; j<n; ++j) {
cin >> dd;
Integer k = i + j*n;
a_in[k] = dd;
a[k] = a_in[k];
}
}

// Read the matrix B, register and copy
for (int i = 0; i<n; ++i) {
for (int j = 0; j<nrhs; ++j) {
cin >> dd;
Integer k = i + j*n;
b_in[k] = dd;
if (j==0) {
}
b[k] = b_in[k];
}
}

// Create AD configuration data object
ifail = 0;

// Solve AX = B
ifail = 0;

// Print Solution
for (int i = 0; i<n; i++) {
for (int j = 0; j<nrhs; j++) {
int k = i + j*n;
}
}
NagError  fail;
INIT_FAIL(fail);
x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,nrhs,br,n,
"  Solution",0,&fail);

cout << "\n Derivatives calculated: First order adjoints\n";
cout << " Computational mode    : algorithmic\n";
cout << "\n Derivatives of solution X w.r.t. RHS B (A inverse)\n";

// Obtain derivatives
for (int i=0; i<n; i++) {

// Reset adjoints, initialize derivative, and evaluate adjoint
double inc = 1.0;
ifail = 0;

for (int j=0; j<n; j++) {
ar[i+j*n] = dd;
}
}
// Print derivatives
cout << endl;
INIT_FAIL(fail);
x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
"           dx(i,1)/db(j,1)",0,&fail);

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