# You are the "computer expert" of a local Athletic Association (C.A.A.). Many teams of runners come to compete. Each time you get a string of all race results of every team who has run. For example here is a string showing the individual results of a team of 5:

# "01|15|59, 1|47|6, 01|17|20, 1|32|34, 2|3|17"

# Each part of the string is of the form: h|m|s where h, m, s are positive or null integer (represented as strings) with one or two digits. There are no traps in this format.

# To compare the results of the teams you are asked for giving three statistics; range, average and median.

# Range : difference between the lowest and highest values. In {4, 6, 9, 3, 7} the lowest value is 3, and the highest is 9, so the range is 9 − 3 = 6.

# Mean or Average : To calculate mean, add together all of the numbers in a set and then divide the sum by the total count of numbers.

# Median : In statistics, the median is the number separating the higher half of a data sample from the lower half. The median of a finite list of numbers can be found by arranging all the observations from lowest value to highest value and picking the middle one (e.g., the median of {3, 3, 5, 9, 11} is 5) when there is an odd number of observations. If there is an even number of observations, then there is no single middle value; the median is then defined to be the mean of the two middle values (the median of {3, 5, 6, 9} is (5 + 6) / 2 = 5.5).

# Your task is to return a string giving these 3 values. For the example given above, the string result will be

# "Range: 00|47|18 Average: 01|35|15 Median: 01|32|34"

# of the form:

# "Range: hh|mm|ss Average: hh|mm|ss Median: hh|mm|ss"

# where hh, mm, ss are integers (represented by strings) with each 2 digits.

# Remarks:

# if a result in seconds is ab.xy... it will be given truncated as ab.
# if the given string is "" you will return ""

require 'minitest/autorun'

def results(string)
	return '' if string.nil? || string.empty?

	score_ary = parse_score_string(string).sort!
	len = score_ary.length

	# get stats truncated to nearest string
	stats = { range: score_ary.max - score_ary.min,
						average: score_ary.inject(&:+)/len,
						median: (score_ary[(len-1)/2] + score_ary[(len/2)])/2 }

	[:range, :average, :median].map { |stat| "#{stat.to_s.capitalize}: #{sec_to_str(stats[stat])}" }.join(' ')
end

def parse_score_string(str)
	str.split(/,/).map { |stat| str_to_sec(stat) }
end

def str_to_sec(str)
	ary_to_s str.split('|').map(&:to_i)
end

def ary_to_s(hms)
	3600* hms[0] + 60*hms[1] + hms[2]
end

def sec_to_str(sec)
	"%02d|%02d|%02d" % [sec / 3600, sec % 3600 / 60 , sec % 60]
end

class RaceStatsTest < MiniTest::Test
	def test_short_strings
		assert_equal(results(''), '')
		assert_equal(results('01|15|59, 1|47|6, 01|17|20, 1|32|34, 2|3|17'), 'Range: 00|47|18 Average: 01|35|15 Median: 01|32|34')
		assert_equal(results('02|15|59, 2|47|16, 02|17|20, 2|32|34, 2|17|17, 2|22|00, 2|31|41'), 'Range: 00|31|17 Average: 02|26|18 Median: 02|22|00')
	end
end