Contents

#include "all_your_base.h"
#include <math.h>
#include <string.h>

size_t rebase(int8_t digits[DIGITS_ARRAY_SIZE], int16_t from_base,
              int16_t to_base, size_t num_digits)
{
   uint16_t denary = 0;
   size_t new_num_digits = 0;

   if ((from_base <= 1) || (to_base <= 1) || (num_digits <= 0))
      return 0;                 /* invalid bases or length */
   if (digits[0] == 0)
      return 0;                 /* leading zeros */

   /* convert to denary */
   for (size_t i = 0; i < num_digits; ++i) {
      if (digits[i] < 0)
         return 0;              /* negative digits */
      if (digits[i] >= from_base)
         return 0;              /* invaid positive digit */
      denary += digits[i] * pow(from_base, (num_digits - i - 1));
   }

   /* calculate number of new digits */
   for (uint16_t j = denary; j > 0;) {
      j /= to_base;
      ++new_num_digits;
   }

   /* calculate and store new digits */
   for (size_t i = new_num_digits - 1; denary > 0; --i) {
      digits[i] = denary % to_base;
      denary /= to_base;
   }

   /* ensure rest of array is zero */
   memset(&digits[new_num_digits], 0, DIGITS_ARRAY_SIZE - new_num_digits);

   return new_num_digits;
}

Version data entries

30 entries across 30 versions & 1 rubygems

Version	Path
trackler-2.2.1.70	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.69	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.68	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.67	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.66	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.65	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.64	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.63	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.62	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.61	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.60	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.59	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.58	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.57	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.56	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.55	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.54	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.53	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.52	tracks/c/exercises/all-your-base/src/example.c
trackler-2.2.1.51	tracks/c/exercises/all-your-base/src/example.c