ex_3-6.c

   1 #include <stdio.h>
   2
   3 void print_array(char s[])
   4 {
   5         int i;
   6         for(i = 0; i <= strlen(s)-1; i++)
   7         {
   8                 putchar(s[i]);
   9         }
  10 }
  11
  12 /* reverse chars in array */
  13 void reverse(char s[])
  14 {
  15         int c,i,j;
  16         for(i = 0, j = strlen(s)-1; i < j; i++, j--)
  17         {
  18                 c = s[i];
  19                 s[i] = s[j];
  20                 s[j] = c;
  21         }
  22 }
  23
  24 /* convert ingteger into a string of chars */
  25 void itoa(int n, char s[])
  26 {
  27         int i, sign;
  28         if((sign = n)< 0)
  29                 n = -n;
  30         i = 0;
  31         do {
  32                 s[i++] = n % 10 + '0';
  33         } while ((n /= 10 ) > 0 );
  34         if(sign < 0)
  35                 s[i++] = '-';
  36         s[i] = '\0';
  37         reverse(s);
  38 }
  39
  40 int main()
  41 {
  42         int n = 123422;
  43         char s[100];
  44
  45         itoa(n, s);
  46         print_array(s);
  47         return 0;
  48 }