String copy

/* strcpy:copy t to s;array subscript version */
void strcpy(char *s, char *t)
{
   int i;

   i = 0;
   while ((s[i] = t[i]) != '\0')
           i++;
}
/* strcpy: copy t to s; pointer version 1 */
void strcpy((*s = *t) != '\0') {
     s++;
     t++;
}

/* strcpy: copy t to s; pointer version 2 */
void strcpy(char *s, char *t) {
     while (( *s++ = *t++)  != '\0')
            ;
}
/* strcpy: copy t to s ; pointer version 3 */
void strcpy(char *s, char *t){
     while (*s++ = *t++)
            ;
}