Project Euler Problem 17

Problem 17

17 May 2002

 

If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.

If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?

NOTE: Do not count spaces or hyphens. For example, 342 (three hundred and forty-two) contains 23 letters and 115 (one hundred and fifteen) contains 20 letters. The use of "and" when writing out numbers is in compliance with British usage.

 

Answer: 21124

C#

 

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Numerics;  namespace Euler {     class Program {         static string[] words = {"",             "one",             "two",             "three",             "four",             "five",             "six",             "seven",             "eight",             "nine",             "ten",             "eleven",             "twelve",             "thirteen",             "fourteen",             "fifteen",             "sixteen",             "seventeen",             "eighteen",             "nineteen"};         static string[] wordsTy = { "",             "",             "twenty",             "thirty",             "forty",             "fifty",             "sixty",             "seventy",             "eighty",             "ninety"};         static string toWords(int n) {             if (n <= 19) return words[n];             if (n <= 99) return wordsTy[n / 10] + words[n % 10];             if (n == 1000) return "onethousand";             string s;             s = words[n / 100] + "hundred";             if (n % 100 > 0)                 s += "and" + toWords(n % 100);             return s;         }          static void Main(string[] args) {             Console.WriteLine(Enumerable.Range(1, 1000).Select(x => toWords(x).Length).Sum());             Console.ReadKey();         }     } }

 

 

Racket

 

(define words
  #(""
    "one"
    "two"
    "three"
    "four"
    "five"
    "six"
    "seven"
    "eight"
    "nine"
    "ten"
    "eleven"
    "twelve"
    "thirteen"
    "fourteen"
    "fifteen"
    "sixteen"
    "seventeen"
    "eighteen"
    "nineteen"))

(define wordsTy
  #(""
    ""
    "twenty"
    "thirty"
    "forty"
    "fifty"
    "sixty"
    "seventy"
    "eighty"
    "ninety"))

(define (toWords n)
  (cond [(<= n 19) (vector-ref words n)]
        [(<= n 99) (string-append (vector-ref wordsTy (quotient n 10)) (vector-ref words (modulo n 10)))]
        [(= n 1000) "onethousand"]
        [else
         (let ([s (string-append (vector-ref words (quotient n 100)) "hundred")])
           (when (> (modulo n 100) 0) (set! s (string-append s "and" (toWords (modulo n 100)))))
           s)]))

(define (problem17)
  (display (stream-fold + 0 (stream-map (lambda (x) (string-length (toWords x))) (in-range 1 1001)))))

(problem17)

 

Javascript

var words = ["",
    "one",
    "two",
    "three",
    "four",
    "five",
    "six",
    "seven",
    "eight",
    "nine",
    "ten",
    "eleven",
    "twelve",
    "thirteen",
    "fourteen",
    "fifteen",
    "sixteen",
    "seventeen",
    "eighteen",
    "nineteen"];
var wordsTy = [ "",
    "",
    "twenty",
    "thirty",
    "forty",
    "fifty",
    "sixty",
    "seventy",
    "eighty",
    "ninety"];
function toWords(n) {
    if (n <= 19) return words[n];
    if (n <= 99) return wordsTy[Math.floor(n / 10)] + words[n % 10];
    if (n == 1000) return "onethousand";
    var s;
    s = words[Math.floor(n / 100)] + "hundred";
    if (n % 100 > 0)
        s += "and" + toWords(n % 100);
    return s;
}

function problem17() {
  var sum=0;
  for (var x=1;x<=1000;x++) {
    sum+=toWords(x).length;
  }
  alert(sum);
}

problem17();

 

Julia:

words = ["",
    "one",
    "two",
    "three",
    "four",
    "five",
    "six",
    "seven",
    "eight",
    "nine",
    "ten",
    "eleven",
    "twelve",
    "thirteen",
    "fourteen",
    "fifteen",
    "sixteen",
    "seventeen",
    "eighteen",
    "nineteen"]

wordsTy = ["",
    "",
    "twenty",
    "thirty",
    "forty",
    "fifty",
    "sixty",
    "seventy",
    "eighty",
    "ninety"]

function toWords(n)
    if n <= 19 return words[begin + n] end
    if n <= 99 return wordsTy[begin + Int(floor(n / 10))] * toWords(n % 10) end
    if n == 1000 return "onethousand" end

    s = words[begin + Int(floor(n / 100))] * "hundred"
    if n % 100 > 0
        s *= "and" * toWords(n % 100)
    end
    return s
end

function problem17()
    sum=0
    for x in 1:1000
        sum += length(toWords(x))
    end
    print(sum)
end

problem17()