Given a non-negative integer up to $999\\,999\\,999$, write it in English.

The input number can be in any form other than English (though you'll typically want to use the native integer type of your language).

When there are several variants of writing the number in English, you can choose whichever suits you more. For example, the input $120$ may give the output one hundred twenty or one hundred and twenty.

The numbers must be formatted as follows:

• Two-digit numbers must be written with dashes where applicable e.g. twenty-five, not twenty five.

• powers of ten start with “one”, e.g. one hundred, not just hundred.

• The tens/ones part, if not zero, must be separated from the hundreds part with and, e.g. two hundred and five, not two hundred five.

• The above rules are applied also to the factors of thousand and million.

• moreover the global tens/ones part has bto be separated by and whenever anything larger is present, even if the hundreds part is missing.

• Adjacent words must be separated by a single space, or a single dash without space where applicable.

• Leading and/or trailing spaces are not allowed. However, if the result is printed, a single trailing newline (not preceded by any spaces) is allowed.

Ungolfed reference implementation

Test cases:

        0 zero
        1 one
        4 four
       10 ten
       16 sixteen
       42 forty-two
      125 one hundred and twenty-five
     1024 one thousand and twenty-four
     1100 one thousand one hundred
    12345 twelve thousand three hundred and forty-five
  1000000 one million
  1000001 one million and one
  7023000 seven million twenty-three thousand
 11012021 eleven million twelve thousand and twenty-one
999999999 nine hundred and ninety-nine million nine hundred and ninety-nine thousand nine hundred and ninety-nine

posted over 2 years ago

CC BY-SA 4.0

10mo ago by trichoplax‭

celtschk‭

1294 reputation 27 43 168 69