problem017.py

# 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.

from common_funcs import answer

def solve():
    #full disclosure: i hate this problem so im not trying to do it elegantly
    total = 0

    #zero (no chars), one, two, three, four, five, six, seven, eight, nine, ten, eleven,
    #twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen
    ones  = [0, 3, 3, 5, 4, 4, 3, 5, 5, 4, 3, 6, 6, 8, 8, 7, 7, 9, 8, 8] 

    #twenty, thirty, forty, fifty, sixty, seventy, eighty, ninety
    tens = [6, 6, 5, 5, 5, 7, 6, 6]

    total = 0
    total99 = 0

    #0-19
    total = total + sum(ones)

    #20-99
    for x in tens:
        for y in ones[0:10]:
            total = total + x + y
    total99 = total

    #100
    total = total + 10 #one hundred

    #101-199
    total = total + total99 + 99*13 #one hundred and
    
    #200
    total = total + 10 #two hundred
    
    #201-299
    total = total + total99 + 99*13 #two hundred and

    #300
    total = total + 12 #three hundred

    #301-399
    total = total + total99 + 99*15 #three hundred and
    
    #400
    total = total + 11 #four hundred
    
    #401-499
    total = total + total99 + 99*14 #four hundred and
    
    #500
    total = total + 11 #five hundred

    #501-599
    total = total + total99 + 99*14 #five hundred and
    
    #600
    total = total + 10 #six hundred
    
    #601-699
    total = total + total99 + 99*13 #six hundred and

    #700
    total = total + 12 #seven hundred

    #701-799
    total = total + total99 + 99*15 #seven hundred and
    
    #800
    total = total + 12 #eight hundred
    
    #801-899
    total = total + total99 + 99*15 #eight hundred and
    
    #900
    total = total + 11 #nine hundred
    
    #901-999
    total = total + total99 + 99*14 #nine hundred and

    #1000
    total = total + 11 # "one thousand"
    
    return total

answer(solve)