ex_3-5.c

   1 #include <stdio.h>
   2 #include <string.h>
   3
   4 int itob(int n, char s[], int b);
   5 void reverse(char s[]);
   6
   7 void print_array(char s[])
   8 {
   9         int i;
  10         for(i = 0; i < strlen(s); i++)
  11                 printf("%c", s[i]);
  12         printf("\n");
  13 }
  14
  15 //main displays same number from base of two to highest base
  16 int main()
  17 {
  18
  19         int base, number = 16384;
  20         char ans[255] = { '\0' };
  21         for(base = 2; base < 62; ++base)
  22         {
  23                 if(itob(number, ans, base))
  24                 {
  25                         printf("Number: %d\tBase: %d Ans: ", number, base);
  26                         print_array(ans);
  27                 }
  28         }
  29         return 0;
  30 }
  31
  32 int itob(int n, char s[], int b)
  33 {
  34         int sign, i = 0;
  35
  36         //create string of digits used to represent chars
  37         char base_chars[] = { "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" };
  38
  39         //check that base is neither too high nor too small
  40         if(b < 2)
  41         {
  42                 printf("Base must be between 2 and %d.\n", (int)strlen(base_chars)-1);
  43                 return -1;
  44         }
  45
  46         if(b > strlen(base_chars)-1)
  47         {
  48                 printf("Base must be %d or less.\n", (int)strlen(base_chars)-1);
  49                 return -1;
  50         }
  51
  52         // remove sign from number
  53         if(n < 0) { n = -n; sign = 1; }
  54
  55
  56         // increment s array and store in that location the modulus of the number -vs- the base
  57         // while number divided by base is larger than 0
  58         i = 0;
  59         do {
  60                 s[i++] = base_chars[n % b];
  61         } while ((n /= b) > 0);
  62
  63         // add sign from above
  64         if(sign == '1') { s[++i] = '-'; }
  65         s[i] = '\0';
  66
  67         reverse(s);
  68         return 1;
  69 }
  70
  71 // reverse string created (it was created in reverse order)
  72 void reverse(char s[])
  73 {
  74         int temp, i, j;
  75         for(i = 0, j = strlen(s)-1; j > i; i++, j--)
  76         {
  77                 temp = s[i];
  78                 s[i] = s[j];
  79                 s[j] = temp;
  80         }
  81 }