Adam Lum's solution to RPCFN #2 (Average Arrival Time for a Flight)

average_time_of_day.rb

# Adam Lum's solution to RPCFN #2
# http://rubylearning.com/blog/2009/10/08/rpcfn-average-arrival-time-for-a-flight-2/

require 'time'

SECONDS_TO_CHECK_FOR = 10800 # Assuming 3 hours is a decent difference check
SECONDS_IN_DAY = 86400

def average_time_of_day(times)
  count_greater = 0
  total = 0
  previous_time_seconds = 0
  seconds_array = []
  times.each do |time|
    seconds_array << Time.parse(time).to_i
  end
  seconds_array.sort!
  seconds_array.each do |s|
    if (previous_time_seconds != 0)
      if ((s - previous_time_seconds).abs >= SECONDS_TO_CHECK_FOR)
        count_greater += 1
      end
    end
    previous_time_seconds = s
  end
  if (count_greater > 0)
    if (count_greater >= (times.size / 2))
      previous_time_seconds = 0
      (0..seconds_array.size - 1).each do |i|
        if ((seconds_array[i] - previous_time_seconds).abs >= SECONDS_TO_CHECK_FOR)
          seconds_array[i] -= SECONDS_IN_DAY
        end
        previous_time_seconds = seconds_array[i]
      end
    else
      previous_time_seconds = 0
      (0..seconds_array.size - 1).each do |i|
        if ((seconds_array[i] - previous_time_seconds).abs >= SECONDS_TO_CHECK_FOR)
          previous_time_seconds = 0
          (0..seconds_array.size - 1).each do |i|
            if ((seconds_array[i] - previous_time_seconds).abs >= SECONDS_TO_CHECK_FOR)
              seconds_array[i] += SECONDS_IN_DAY
            end
            previous_time_seconds = seconds_array[i]
          end
        end
      end
    end
  end
  Time.at(seconds_array.inject {|sum,n| sum += n } / times.size).strftime("%I:%M%p").downcase
end