GopherProxy

	04-median.c - libzahl - big integer library
	git clone git://git.suckless.org/libzahl
	Log
	Files
	Refs
	README
	LICENSE
	---
	04-median.c (1167B)
	---
	1 /* Calculates the median of $@ */
	2
	3 #include <stdio.h>
	4 #include <stdlib.h>
	5
	6 #include <zahl.h>
	7
	8 int
	9 main(int argc, char *argv[])
	10 {
	11 struct zahl *values;
	12 z_t med, medmod;
	13 jmp_buf env;
	14 char buf, argv0;
	15 int i, j;
	16
	17 argv0 = *argv++, argc--;
	18
	19 if (!argc) {
	20 fprintf(stderr,
	21 "%s: cannot calculate median of the empty bag\n",
	22 argv0);
	23 return 1;
	24 }
	25
	26 values = calloc(argc, sizeof(*values));
	27 if (!values)
	28 return perror(argv0), 1;
	29
	30 if (setjmp(env))
	31 return zperror(argv0), 1;
	32
	33 zsetup(env);
	34 zinit(med);
	35 zinit(medmod);
	36
	37 /* Since `values` where allocated with
	38 * `calloc` it is already cleared and
	39 * `zinit` is not necessary. */
	40
	41 for (i = 0; i < argc; i++)
	42 zsets(&values[i], argv[i]);
	43
	44 qsort(values, argc, sizeof(*values),
	45 (int ()(const void , const void *))zcmp);
	46 i = argc / 2;
	47 j = i - !(argc & 1);
	48 zadd(med, &values[i], &values[j]);
	49 zsetu(medmod, 2);
	50 zdivmod(med, medmod, med, medmod);
	51
	52 printf("%s%s\n", buf = zstr(med, NULL, 0),
	53 (const char *[]){"", ".5"}[zodd(medmod)]);
	54 free(buf);
	55
	56 zfree(medmod);
	57 zfree(med);
	58 for (i = 0; i < argc; i++)
	59 zfree(&values[i]);
	60 free(values);
	61 zunsetup();
	62 return 0;
	63 }