```/* nag_prod_limit_surviv_fn (g12aac) Example Program.
*
* NAGPRODCODE Version.
*
* Copyright 2016 Numerical Algorithms Group.
*
* Mark 26, 2016.
*
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagg12.h>

int main(void)
{

Integer exit_status = 0, i, *ic = 0, *ifreq = 0, n, nd;
NagError fail;
double *p = 0, *psig = 0, *t = 0, *tp = 0;

INIT_FAIL(fail);

printf("nag_prod_limit_surviv_fn (g12aac) Example Program Results\n");

/* Skip heading in data file */
scanf("%*[^\n] ");
scanf("%" NAG_IFMT " ", &n);
if (n >= 2) {
if (!(psig = NAG_ALLOC(n, double)) ||
!(p = NAG_ALLOC(n, double)) ||
!(t = NAG_ALLOC(n, double)) ||
!(tp = NAG_ALLOC(n, double)) ||
!(ifreq = NAG_ALLOC(n, Integer)) || !(ic = NAG_ALLOC(n, Integer)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
}
else {
printf("Invalid n.\n");
exit_status = 1;
return exit_status;
}

for (i = 0; i < n; ++i)
scanf("%lf %" NAG_IFMT " %" NAG_IFMT " ", &t[i], &ic[i], &ifreq[i]);

/* nag_prod_limit_surviv_fn (g12aac).
* Computes Kaplan-Meier (product-limit) estimates of
* survival probabilities
*/
nag_prod_limit_surviv_fn(n, t, ic, ifreq, &nd, tp, p, psig, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_prod_limit_surviv_fn (g12aac).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

printf("\n   Time   Survival    Standard\n");
printf("         probability  deviation\n\n");
for (i = 0; i < nd; ++i)
printf(" %6.1f%10.3f  %10.3f\n", tp[i], p[i], psig[i]);

END:
NAG_FREE(psig);
NAG_FREE(p);
NAG_FREE(t);
NAG_FREE(tp);
NAG_FREE(ifreq);
NAG_FREE(ic);
return exit_status;
}
```