```/* nag_sparse_nsym_fac (f11dac) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*/

#include <nag.h>
#include <nag_stdlib.h>
#include <nag_string.h>
#include <stdio.h>
#include <nagf11.h>

int main(void)
{
double dtol;
double *a = 0;
Integer *icol = 0, *irow = 0, *istr = 0, *idiag = 0, *ipivp = 0;
Integer *ipivq = 0;
Integer nnzc, exit_status = 0, i, n, lfill, npivm, nnz, num;
char nag_enum_arg[40];
Nag_SparseNsym_Fact milu;
Nag_SparseNsym_Piv pstrat;
NagError fail;

INIT_FAIL(fail);

printf("nag_sparse_nsym_fac (f11dac) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%*[^\n]", &n);
scanf("%" NAG_IFMT "%*[^\n]", &nnz);
scanf("%" NAG_IFMT "%lf%*[^\n]", &lfill, &dtol);
scanf("%39s%*[^\n]", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
pstrat = (Nag_SparseNsym_Piv) nag_enum_name_to_value(nag_enum_arg);
scanf("%39s%*[^\n]", nag_enum_arg);
milu = (Nag_SparseNsym_Fact) nag_enum_name_to_value(nag_enum_arg);

num = 2 * nnz;
istr = NAG_ALLOC(n + 1, Integer);
idiag = NAG_ALLOC(n, Integer);
ipivp = NAG_ALLOC(n, Integer);
ipivq = NAG_ALLOC(n, Integer);
irow = NAG_ALLOC(num, Integer);
icol = NAG_ALLOC(num, Integer);
a = NAG_ALLOC(num, double);

if (!istr || !idiag || !ipivp || !ipivq || !irow || !icol || !a) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
return exit_status;
}

/* Read the matrix a */

for (i = 1; i <= nnz; ++i)
scanf("%lf%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &a[i - 1], &irow[i - 1],
&icol[i - 1]);

/* Calculate incomplete LU factorization */

/* nag_sparse_nsym_fac (f11dac).
* Incomplete LU factorization (nonsymmetric)
*/
nag_sparse_nsym_fac(n, nnz, &a, &num, &irow, &icol, lfill, dtol, pstrat,
milu, ipivp, ipivq, istr, idiag, &nnzc, &npivm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_sparse_nsym_fac (f11dac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Output original matrix */

printf("  Original Matrix \n  n     = %6" NAG_IFMT "\n", n);
printf("  nnz   = %6" NAG_IFMT "\n", nnz);

for (i = 1; i <= nnz; ++i)
printf("%8" NAG_IFMT "%16.6e%8" NAG_IFMT "%8" NAG_IFMT "\n", i, a[i - 1],
irow[i - 1], icol[i - 1]);
printf("\n");

/* Output details of the factorization */

printf("  Factorization \n  n     = %6" NAG_IFMT "\n", n);
printf("  nnz   = %6" NAG_IFMT "\n", nnzc);
printf("  npivm = %6" NAG_IFMT "\n", npivm);

for (i = nnz + 1; i <= nnz + nnzc; ++i)
printf("%8" NAG_IFMT "%16.6e%8" NAG_IFMT "%8" NAG_IFMT "\n", i, a[i - 1],
irow[i - 1], icol[i - 1]);

printf("\n         i       ipivp[i-1]  ipivq[i-1] \n"); /* */

for (i = 1; i <= n; ++i)
printf("%10" NAG_IFMT "%10" NAG_IFMT "%10" NAG_IFMT "\n", i, ipivp[i - 1],
ipivq[i - 1]);

END:
NAG_FREE(istr);
NAG_FREE(idiag);
NAG_FREE(ipivp);
NAG_FREE(ipivq);
NAG_FREE(irow);
NAG_FREE(icol);
NAG_FREE(a);

return exit_status;
}
```