srs_lib.c

   1 #include <stdio.h>
   2 #include <string.h>
   3
   4 #include "srs_lib.h"
   5
   6 /* print contents of array */
   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 /* print contents of array */
  16 void print_sparse_array(char s[][MAXLEN])
  17 {
  18         int i, j;
  19         for(i = 0; i < MAXLINES; i++)
  20         {
  21                 int found = 0;
  22                 for(j = 0; j < MAXLEN; j++)
  23                 {
  24                         if(s[i][j] != '\0') { found++; }
  25                 }
  26                 if(found > 0)
  27                 {
  28                         printf("%d:\t", i);
  29                         for(j = 0; j < MAXLEN; j++)
  30                                 printf("%c", s[i][j]);
  31                         printf("\n");
  32                 }
  33         }
  34         printf("\n");
  35 }
  36
  37 /* reverse contents of array in place */
  38 void reverse(char s[])
  39 {
  40         int c, i, j;
  41         for(i = 0, j = strlen(s)-1; i < j; i++, j--)
  42         {
  43                 c = s[i];
  44                 s[i] = s[j];
  45                 s[j] = c;
  46         }
  47 }
  48
  49 /* convert integer to another base and store result in array of char */
  50 int itob(int n, char s[], int b)
  51 {
  52         int sign, i = 0;
  53
  54         //create string of digits used to represent chars
  55         char base_chars[] = { "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" };
  56
  57         //check that base is neither too high nor too small
  58         if(b < 2)
  59         {
  60                 printf("Base must be between 2 and %d.\n", (int)strlen(base_chars)-1);
  61                 return -1;
  62         }
  63
  64         if(b > strlen(base_chars)-1)
  65         {
  66                 printf("Base must be %d or less.\n", (int)strlen(base_chars)-1);
  67                 return -1;
  68         }
  69
  70         // remove sign from number
  71         if(n < 0) { n = -n; sign = 1; }
  72
  73
  74         // increment s array and store in that location the modulus of the number -vs- the base
  75         // while number divided by base is larger than 0
  76         i = 0;
  77         do {
  78                 s[i++] = base_chars[n % b];
  79         } while ((n /= b) > 0);
  80
  81         // add sign from above
  82         if(sign == '1') { s[++i] = '-'; }
  83         s[i] = '\0';
  84
  85         reverse(s);
  86         return 1;
  87 }
  88