```/* E02BC_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;

int main(void)
{
Integer exit_status = 0;

cout << "E02BC_A1W_F C++ Header Example Program\n";

Integer ifail = 0;

// Skip heading in data file
string mystr;
getline (cin, mystr);

Integer ncap, m;
cin >> ncap; cin >> m;

Integer ncap7 = ncap + 7;

if (m <= 0) {
printf("Invalid m.\n");
exit_status = 1;
return exit_status;
}
if (ncap <= 0) {
printf("Invalid ncap.\n");
exit_status = 1;
return exit_status;
}

// Allocate arrays
nagad_a1w_w_rtype  *c = 0, *lamda = 0;
double    *dsdl = 0, *dsdc = 0;
dsdc  = new double [2*m*ncap7];
dsdl  = new double [2*m*ncap7];

// Read knots and spline coefficients from file
double tmp;
for (int j = 0; j < ncap7; j++) {
cin >> tmp;
lamda[j] = tmp;
}
for (int j = 0; j < ncap + 3; j++) {
cin >> tmp;
c[j] = tmp;
}

cout << "\n        x             Spline    1st deriv";
cout << "   2nd deriv   3rd deriv\n";
cout.setf(ios::scientific,ios::floatfield);
cout.setf(ios::right);
cout.precision(4);

for (int i = 0; i < m; i++) {
cin >> tmp;
x = tmp;

for (Integer left = 1; left <= 2; left++) {
for (int l = 0; l < ncap7; l++) {
}
for (int l = 0; l < ncap7; l++) {
}

e02bc_a1w_f_(ad_handle, ncap7, lamda, c, x, left, s, ifail);

if (ifail != 0) {
printf("\nError from e02bc_a1w_f_.\n%" NAG_IFMT "\n", ifail);
exit_status = 1;
return exit_status;
}

cout.width(11); cout << xv;

if (left == 1) {
cout << "   Left";
} else {
cout << "  Right";
}
for (int l = 0; l < 4; l++) {
cout.width(12); cout << tmp;
}

Integer indx = (left-1)*m*ncap7 + i*ncap7;
for (int l = 0; l < ncap7; l++) {
dsdl[indx + l] = tmp;
dsdc[indx + l] = tmp;
}
cout << "\n";
}
cout << "\n";
}

cout << "\n Derivatives of spline values with respect to knots\n";
NagError  fail;
INIT_FAIL(fail);
x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,ncap7,m,dsdl,ncap7,
"Left:  ds/dlamda",0,&fail);
cout << "\n";
x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,ncap7,m,&dsdl[m*ncap7],
ncap7, "Right: ds/dlamda",0,&fail);
cout << "\n\n Derivatives with respect to spline coefficients\n";

x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,ncap7,m,dsdc,ncap7,
"Left:  ds/dC",0,&fail);
cout << "\n";
x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,ncap7,m,&dsdc[m*ncap7],
ncap7, "Right: ds/dC",0,&fail);