```/* nag_real_eigenvalues (f02afc) Example Program.
*
* Copyright 2014 Numerical Algorithms Group.
*
* Mark 2 revised, 1992.
* Mark 8 revised, 2004.
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagf02.h>

#define COMPLEX(A) A.re, A.im
#define A(I, J)    a[(I) *tda + J]

int main(void)
{
Complex  *r = 0;
Integer  exit_status = 0, i, *iter = 0, j, n, tda;
NagError fail;
double   *a = 0;

INIT_FAIL(fail);

printf("nag_real_eigenvalues (f02afc) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%ld", &n);
if (n >= 1)
{
if (!(a = NAG_ALLOC(n*n, double)) ||
!(iter = NAG_ALLOC(n, Integer)) ||
!(r = NAG_ALLOC(n, Complex)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
tda = n;
}
else
{
printf("Invalid n.\n");
exit_status = 1;
return exit_status;
}
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
scanf("%lf", &A(i, j));
/* nag_real_eigenvalues (f02afc).
* All eigenvalues of real matrix
*/
nag_real_eigenvalues(n, a, tda, r, iter, &fail);
if (fail.code != NE_NOERROR)
{
printf("Error from nag_real_eigenvalues (f02afc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

printf("Eigenvalues\n");
for (i = 0; i < n; i++)
printf("( %7.3f ,  %7.3f ) \n", COMPLEX(r[i]));
END:
NAG_FREE(a);
NAG_FREE(iter);
NAG_FREE(r);
return exit_status;
}
```