palindrome.ytl

// obdobne pro dalsi ciselne typy
i32 i32_from_string([-]u8 s) {
  i32 ret = 0;
  bool zaporne = false;
  i64 i = 1;
  if ((u8 c = s[0]) == 45) { zaporne = true; c = s[i++] }
  do {
    i32 const = 214748364;  // == floor(2**31 / 10)
    if (ret<=const && (ret!=const || c-48<=(zaporne??8:7)) && 48<=c<58) {
      ret = 10*ret + (c - 48);
    } else { @exit(1) }
    c = s[i++];
  } while (c != 0);
  return zaporne ?? -ret : ret;
}

// vysledek je dynamicky alokovany a musi se kdyztak uvolnit z pameti
[-]u8 string_from_i64(i64 n) {
  [-]u8 temp = "-0123456789012345678";
  if (bool zaporne = (n < 0)) { n *= -1 }
  i64 i = 19;
  do { temp[i--] = 48 + (@u8(n) % 10); n /= 10 } while (n > 0);
  i64 delka = (19 - i) + (zaporne ? temp[i--] = 45; 1 : 0);
  [-]u8 preret = @[-]u8(@malloc(8 + delka + 1));
  @[]i64(preret)[] = delka;
  [-]u8 ret = @[-]u8(preret[8]#);
  for (i64 j = 0, i++; j<=delka, j++) { ret[j] = temp[i] }
  return ret;
}

bool is_palindrome([-]u8 input_string) {
  for (i64 i = 0; i64 j = @len(input_string)-1,
       i < j,
       i++; j--) {
    if (input_string[i] != input_string[j]) { return false }
  }
  return true;
}

i32 main() {
  [-]u8 s;
  @print("your first input: ");
  do {
    s = @readln();
    if (is_palindrome(s)) { @print("YES, a palindrome") } else { @print("NO, not a palindrome") };
    @print(@[-]u8 [ 10, 0 ]);
    @print "that was of length ";
    @print string_from_i64(@len s);
    @print(@[-]u8 [ 10, 0 ]);
    @print("your next input: ");
    @free(s);
  } while (@len(s) != 0)
  return 0;
}