NAG Library Manual, Mark 28.3
```/* F11DB_P0W_F C++ Header Example Program.
*
* Copyright 2022 Numerical Algorithms Group.
* Mark 28.3, 2022.
*/
#include <dco.hpp>
#include <iostream>
#include <nag.h>
#include <nagx04.h>
#include <stdio.h>
using namespace std;

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

cout << "F11DB_P0W_F C++ Header Example Program Results\n\n";
// Skip heading in data file
string mystr;
getline(cin, mystr);

// Read order of matrix and number of nonzero entries
Integer n, nnz;
cin >> n;
cin >> nnz;

Integer  la     = 2 * nnz;
Integer  liwork = 7 * n + 2;
double * a = 0, *x = 0, *y = 0;
Integer *icol = 0, *idiag = 0, *ipivp = 0, *ipivq = 0, *irow = 0;
Integer *istr = 0, *iwork = 0;

a     = new double[la];
x     = new double[n];
y     = new double[n];
icol  = new Integer[la];
idiag = new Integer[n];
ipivp = new Integer[n];
ipivq = new Integer[n];
irow  = new Integer[la];
istr  = new Integer[n + 1];
iwork = new Integer[liwork];

for (int i = 0; i < nnz; i++)
{
cin >> a[i] >> irow[i] >> icol[i];
}

for (int i = 0; i < n; i++)
{
cin >> y[i];
}

ifail = 0;
// Calculate LU factorization
Integer lfill = -1;
double  dtol;
Integer nnzc, npivm;
dtol  = 0.0;
ifail = 0;
ipivp, ipivq, istr, idiag, nnzc, npivm, iwork, liwork, ifail);

// Check value of npivm
if (npivm > 0)
{
cout << " Factorization is not complete" << endl;
}
else
{

//       Solve P L D U x = y
ifail = 0;
idiag, "C", y, x, ifail);

// Output results
cout.setf(ios::scientific, ios::floatfield);
cout.precision(4);
cout << "  Solution vector" << endl;
for (int i = 0; i < n; ++i)
{
cout.width(12);
cout << x[i] << "     ";
}
cout << endl;
}

delete[] a;
delete[] x;
delete[] y;
delete[] icol;
delete[] idiag;
delete[] ipivp;
delete[] ipivq;
delete[] irow;
delete[] istr;
delete[] iwork;

return exit_status;
}
```