```/* E04UE_A1W_F C++ Header Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
* Mark 27, 2019.
*/

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

extern "C"
{
Integer &mode,
const Integer &n,
const Integer &nstate,
Integer iuser[],
Integer &mode,
const Integer &ncnln,
const Integer &n,
const Integer &ldcj,
const Integer needc[],
const Integer &nstate,
Integer iuser[],
}

int main(void)
{
// Scalars
int               exit_status = 0;

cout << "E04UE_A1W_F C++ Header Example Program Results\n\n";

// Create AD configuration data object
Integer ifail = 0;

// Skip first line of data file
string mystr;
getline (cin, mystr);

Integer n, nclin, ncnln;
cin >> n;
cin >> nclin;
cin >> ncnln;

Integer liwork = 3*n + nclin + 2*ncnln;
Integer lda = nclin, sda = n, ldcj = ncnln, ldr = n;
Integer lwork;

lwork = 20*n;
if (nclin>0 || ncnln>0) {
lwork = lwork + 2*n*n;
if (nclin>0) {
lwork = lwork + 11*nclin;;
}
if (ncnln>0) {
lwork = lwork + n*nclin + 2*n*ncnln + 21*ncnln;
}
}
if (ncnln>0) {
lwork = lwork + n*nclin + (2*n+21)*ncnln;
}
Integer           lb = n + nclin + ncnln;
nagad_a1w_w_rtype *a=0, *bl=0, *bu=0, *c=0, *cjac=0;
nagad_a1w_w_rtype *objgrd=0, *clamda=0, *r=0, *x=0, *work=0, *rwsav=0;
Integer           *istate=0, *iwork=0, *iwsav=0;
logical           *lwsav=0;
lwsav  = new logical           [120];
istate = new Integer           [lb];
iwork  = new Integer           [liwork];
iwsav  = new Integer           [610];

// Read problem parameters and register for differentiation
double            yr;
for (int i=0; i<nclin; i++) {
for (int j=0; j<sda; j++) {
Integer k = i + j*nclin;
cin >> yr;
a[k] = yr;
}
}
for (int i=0; i<lb; i++) {
cin >> yr;
bl[i] = yr;
}
for (int i=0; i<lb; i++) {
cin >> yr;
bu[i] = yr;
}
for (int i=0; i<n; i++) {
cin >> yr;
x[i] = yr;
}
for (int i=0; i<3; i++) {
ruser[i] = 1.0;
}

// Initialize sav arrays
ifail = 0;
char cwsav[1];
e04wb_a1w_f_("E04UCA",cwsav,1,lwsav,120,iwsav,610,rwsav,475,ifail,6,1);

// Solve the problem
Integer           iter, iuser[1];
ifail = -1;
objfun,iter,istate,c,cjac,clamda,objf,objgrd,r,x,iwork,
liwork,work,lwork,iuser,ruser,lwsav,iwsav,rwsav,ifail);

// Primal results
double inc = 1.0;
cout.setf(ios::scientific,ios::floatfield);
if (ifail==0 || ifail>1) {
cout.precision(4);
cout << "\n Optimal objective function value = ";
cout << "\n Solution point = ";
for (int i=0; i<n; i++) {
}
cout << endl;
} else {
cout << "e04uc_a1w_f_ failed with ifail = " << ifail << endl;
goto END;
}

cout << "\n Derivatives calculated: First order adjoints\n";
cout << " Computational mode    : algorithmic\n\n";
cout << " Derivatives:\n\n";

// Setup evaluation of derivatives of objf via adjoints.
ifail = 0;

// Get derivatives of objf w.r.t. ruser
cout << "  derivatives of x[0] w.r.t ruser[0:2]:\n";
for (int i=0; i<3; i++) {
cout.width(12); cout << d;
if (i%4==3) {
cout << endl;
}
}
cout << endl;
END:
// Remove computational data object and tape

delete [] a;
delete [] bl;
delete [] bu;
delete [] c;
delete [] cjac;
delete [] clamda;
delete [] r;
delete [] x;
delete [] objgrd;
delete [] work;
delete [] rwsav;
delete [] lwsav;
delete [] istate;
delete [] iwork;
delete [] iwsav;
return exit_status;
}

Integer &mode,
const Integer &n,
const Integer &nstate,
Integer iuser[],
{
if (mode==0 || mode==2) {
objf = x[0]*x[3]*(ruser[0]*x[0] + ruser[1]*x[1] + ruser[2]*x[2]) + x[2];
}
if (mode==1 || mode==2) {
objgrd[0] = x[3]*(2.0*ruser[0]*x[0]+ruser[1]*x[1]+ruser[2]*x[2]);
objgrd[1] = x[0]*x[3]*ruser[1];
objgrd[2] = x[0]*x[3]*ruser[2] + 1.0;
objgrd[3] = x[0]*(ruser[0]*x[0]+ruser[1]*x[1]+ruser[2]*x[2]);
}
return;
}
Integer &mode,
const Integer &ncnln,
const Integer &n,
const Integer &ldcj,
const Integer needc[],
const Integer &nstate,
Integer iuser[],
{
if (nstate==1) {
for (int i = 0; i<ncnln*n; ++i) {
cjac[i] = 0.0;
}
}
if (needc[0]>0) {
if (mode==0 || mode==2) {
c[0] = x[0]*x[0] + x[1]*x[1] + x[2]*x[2] + x[3]*x[3];
}
if (mode==1 || mode==2) {
cjac[0]     = x[0] + x[0];
cjac[ncnln] = x[1] + x[1];
cjac[2*ncnln] = x[2] + x[2];
cjac[3*ncnln] = x[3] + x[3];
}
}
if (needc[1]>0) {
if (mode==0 || mode==2) {
c[1] = x[0]*x[1]*x[2]*x[3];
}
if (mode==1 || mode==2) {
cjac[1]         = x[1]*x[2]*x[3];
cjac[ncnln+1]   = x[0]*x[2]*x[3];
cjac[2*ncnln+1] = x[0]*x[1]*x[3];
cjac[3*ncnln+1] = x[0]*x[1]*x[2];
}
}
return;
}
```