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/* Calculates the median of $@ */
#include <stdio.h>
#include <stdlib.h>
#include <zahl.h>
int
main(int argc, char *argv[])
{
struct zahl *values;
z_t med, medmod;
jmp_buf env;
char *buf, *argv0;
int i, j;
argv0 = *argv++, argc--;
if (!argc) {
fprintf(stderr,
"%s: cannot calculate median of the empty bag\n",
argv0);
return 1;
}
values = calloc(argc, sizeof(*values));
if (!values)
return perror(argv0), 1;
if (setjmp(env))
return zperror(argv0), 1;
zsetup(env);
zinit(med);
zinit(medmod);
/* Since `values` where allocated with
* `calloc` it is already cleared and
* `zinit` is not necessary. */
for (i = 0; i < argc; i++)
zsets(&values[i], argv[i]);
qsort(values, argc, sizeof(*values),
(int (*)(const void *, const void *))zcmp);
i = argc / 2;
j = i - !(argc & 1);
zadd(med, &values[i], &values[j]);
zsetu(medmod, 2);
zdivmod(med, medmod, med, medmod);
printf("%s%s\n", buf = zstr(med, NULL, 0),
(const char *[]){"", ".5"}[zodd(medmod)]);
free(buf);
zfree(medmod);
zfree(med);
for (i = 0; i < argc; i++)
zfree(&values[i]);
free(values);
zunsetup();
return 0;
}
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