jwworth

import Graphics.Element exposing (show)
import Array exposing (..)
import String exposing (..)

magicNumber : Array Int
magicNumber =
  let
    isNumber number =  
      String.right 1 (toString(number)) == "6" &&
      (String.append "6" (String.dropRight 1 (toString(number))))

jwworth

-- Week 4: From One End to the Other: Find the smallest possible (positive)
-- integer that ends in a six such that if that six is removed and placed in front
-- of the remaining digits of the number, the resulting number will be four times
-- as large as the original.

function swap_first_and_last(t, n)
  table.insert(t, 1, n)
  return tonumber(table.concat(t))
end

jwworth

# From One End to the Other: Find the smallest possible
# (positive) integer that ends in a six such that if that six is removed and
# placed in front of the remaining digits of the number, the resulting number
# will be four times as large as the original.

i = 6
loop do
  digits = i.to_s.split('')
  if digits.last == '6' && digits.rotate(-1).join.to_i == (i * 4)
    puts i

jwworth

# Week 2 - Vim Buffer: I open up a new Vim buffer and type all the
# numbers 1 to 10,000, separated by spaces. Then, my cat walks on the keyboard
# and somehow activates a substitution command that replaces all the '0’ digits
# (zeros) with spaces. If I now sum up all the numbers in the buffer, as
# delineated by spaces, what is the total?

def vim_buffer(start = 1, limit)
  (start..limit).flat_map { |num| num.to_s.gsub('0', ' ').split }.map(&:to_i).reduce(:+)
end

jwworth

 --[[
  Round Robin
  Given 3 Teams (A, B, C), we want to organize a tournament schedule such that every team plays every other team exactly once. Here is a valid schedule for these 3 teams:

  A - B
  B - C
  A - C
  How about if we have N teams? Devise a general purpose algorithm that generates tournament schedules for N teams.
--]]