range_flatten.rb

# Expected arg to be 2-d array and each sub array to have 2 numbers representing range-start and range-end
# [[1, 4], [6, 6], [6, 8], [1, 10]], expected: [[1, 10]]
# program to solve finding the overlapping ranges and combining them.
def range_flatten(arr)
	res = []; done = []
	arr.each_with_index do |range, i|
		a = range.first; b = range.second
		arr[(i+1)..-1].each_with_index do |other_range, j|
			next if done.include?(i+j+1)
			
			if other_range.first <= b
				done << (i+j+1)
				first_element = [a, other_range.first].min
				second_element = [b, other_range.second].max
				res << [first_element, second_element]
				break
			end
		end
		if res.size > 1
			res_range = res.first
			res_other_range = res.second
			if res_other_range.first <= res_range.second
				first_element = [res_range.first, res_other_range.first].min
				second_element = [res_range.second, res_other_range.second].max
				res = [[first_element, second_element]]
			end
		end
	end
	return res
end