calculate-email-distributions.rb

#!/usr/bin/env ruby

if ARGV.length != 3
  puts 'Need 3 arguments'
  puts '   calculate-email-distribution INITIAL_SIZE STEP AMOUNT'
  puts 'e.g.'
  puts '   calculate-email-distribution 100 20 65000'
  exit 0
end

initialSize = ARGV[0].to_i
step = ARGV[1].to_i
amount = ARGV[2].to_i

header = "Time\tEmails\tTotal\n"
puts header

a = [initialSize]

total = 0
i = 0
loop do
  a.push(a[i] + step)
  break if a.inject(0) {|sum, n| sum + n} >= amount
  i += 1
end

# print
sum = 0
a.length.times do |i|
  sum += a[i]
  hour = (i + 12) % 24
  puts "#{hour}\t#{a[i]}\t#{sum}"
  puts "\n#{header}" if hour == 23
end

# summary
daysItTakes = a.length / 24
hoursItTakes = a.length % 24
if daysItTakes > 0
  puts "It takes #{daysItTakes} day(s) and #{hoursItTakes} hour(s)."
else
  puts "It takes #{hoursItTakes} hour(s)."
end