ex_5-4.c

   1 #include <stdio.h>
   2
   3 /* strcmp - compare strings */
   4 /* return <0 is s < t; 0 if s==t; >0 if s>t */
   5 int strcmp(char *s, char *t)
   6 {
   7         int i;
   8         for(i = 0; s[i] == t[i]; i++)
   9                 ;
  10
  11         return i; // might need to change
  12 }
  13
  14
  15 /* strlen - return length of string */
  16 int strlen_new(char *s)
  17 {
  18         int n;
  19         for(n =0; s[n] != '\0'; n++);
  20         return n;
  21 }
  22
  23 /* strend - compares end of string s with string t */
  24 /* return 1 if string t occurs and 0 otherwise */
  25 int strend(char *s, char *t)
  26 {
  27         int ls, lt;
  28         ls = strlen_new(s); // find length of s
  29         lt = strlen_new(t); // find length of t
  30
  31         // start with end of s and move back comparing with end of t
  32         while(lt >= 0)
  33         {
  34                 if(s[ls] != t[lt]) { return 0; }
  35                 --ls;
  36                 --lt;
  37         }
  38         return 1;
  39 }
  40
  41
  42 int main()
  43 {
  44         char s[] = { "1234567890" };
  45         char t[] = { "67890" };
  46
  47         int ans = strend(s,t);
  48         printf("%d\n", ans);
  49
  50         return 1;
  51 }