int main() {
printf("str = ");
char* str = console_read_line(20, 100);
printf("reverse = %s\n", r_reverse(str, strlen(str), 0));
free(str);
return 0;
}
char* r_reverse(char* str, int len, int i) {
if (i >= len / 2)
return str;
swap_char(&str[i], &str[len - i - 1]);
return r_reverse(str, len, i + 1);
}
/* r_reverse: recursive helper */
void r_reverse(char s[], int left, int right)
{
int tmp;
if (left >= right)
return;
tmp = s[left];
s[left] = s[right];
s[right] = tmp;
r_reverse(s, left+1, right-1);
}
/* reverse: reverse s in place */
void reverse(char s[])
{
r_reverse(s, 0, strlen(s)-1);
}
