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.
In [3]:
def pro_one(num) # 1..19
return "" if num == 0
%w(zero one two three four five six seven eight nine ten eleven twelve thirteen fourteen fifteen sixteen seventeen eighteen nineteen)[num]
end
pro_one(5)
Out[3]:
In [4]:
def pro_ten(num) # 20..99
return pro_one(num) if num < 20
tens = %w(zero ten twenty thirty forty fifty sixty seventy eighty ninety)
ten, one = num.to_s.split("").map{|i|i.to_i}
return tens[ten] + " " + pro_one(one)
end
pro_ten(56)
Out[4]:
In [5]:
def pro_hundred(num) #100..999
return pro_ten(num) if num < 100
return "one thousand" if num == 1000
hun, ten_one = [num.to_s[0].to_i, num.to_s[1..2].to_i]
return pro_one(hun) + " hundred and " + pro_ten(ten_one) if ten_one != 0
return pro_one(hun) + " hundred"
end
pro_hundred(430)
Out[5]:
In [6]:
(1..1000).to_a.map{|i| pro_hundred(i).gsub(/[ \-]/, "").length }.inject &:+
Out[6]:
In [7]:
pro_hundred(115).gsub(/[ \-]/, "").length
Out[7]:
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