Roman - Second pass

gistfile1.rb

#!/usr/bin/env ruby

class Roman

  NUMERALS = {
    1 => 'I',
    4 => 'IV',
    5 => 'V',
    9 => 'IX',
    10 => 'X',
    40 => 'XL',
    50 => 'L',
    90 => 'XC',
    100 => 'C',
    400 => 'CD',
    500 => 'D',
    900 => 'CM',
    1000 => 'M'
  } 
      
  BUCKETS = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
        
  def self.to_roman(i)
    output = ''
    for bucket in BUCKETS
      while (i >= bucket)
        output += NUMERALS[bucket]
        i -= bucket
      end
    end
    return output
  end 
  
end

for i in 1...100
  puts i.to_s + ": " + Roman.to_roman(i)
end

Second pass with those special deduction cases sprinkled in.

1: I
2: II
3: III
4: IV
5: V
6: VI
7: VII
8: VIII
9: IX
10: X
11: XI
12: XII
13: XIII
14: XIV
15: XV
16: XVI
17: XVII
18: XVIII
19: XIX
20: XX
21: XXI
22: XXII
23: XXIII
24: XXIV
25: XXV
26: XXVI
27: XXVII
28: XXVIII
29: XXIX
30: XXX
31: XXXI
32: XXXII
33: XXXIII
34: XXXIV
35: XXXV
36: XXXVI
37: XXXVII
38: XXXVIII
39: XXXIX
40: XL
41: XLI
42: XLII
43: XLIII
44: XLIV
45: XLV
46: XLVI
47: XLVII
48: XLVIII
49: XLIX
50: L