Огнян обнови решението на 26.10.2015 05:47 (преди над 8 години)
+class RationalSequence
+ include Enumerable
+
+ def initialize(limit)
+ @limit = limit
+ end
+
+ def each
+ @rationals = []
+ direction = numerator = denominator = 1
+
+ while @rationals.count < @limit
+ next_rational_number = Rational(numerator, denominator)
+ if !@rationals.include? next_rational_number
+ @rationals.push(next_rational_number)
+ yield next_rational_number
+ end
+
+ iteration = iterate_rational(direction, numerator, denominator)
+ direction = iteration[0]
+ numerator = iteration[1]
+ denominator = iteration[2]
+ end
+ end
+
+ private
+
+ def iterate_rational(direction, numerator, denominator)
+ if direction == 1
+ if denominator == 1
+ numerator += 1
+ direction *= -1
+ else
+ numerator += 1
+ denominator -= 1
+ end
+ else
+ if numerator == 1
+ denominator += 1
+ direction *= -1
+ else
+ numerator -= 1
+ denominator += 1
+ end
+ end
+
+ return direction, numerator, denominator
+ end
+end
+
+class FibonacciSequence
+ include Enumerable
+
+ def initialize(limit, first: 1, second: 1)
+ @limit = limit
+ @first = first
+ @second = second
+ end
+
+ def each
+ current, previous = @first, 0
+
+ while current <= @limit
+ yield current
+ current, previous = current + previous, current
+ end
+ end
+end
+
+class PrimeSequence
+ include Enumerable
+
+ def initialize(limit)
+ @limit = limit
+ end
+
+ def each
+ prime_count = 0
+ number = 2
+
+ while prime_count < @limit
+ if DrunkenMathematician.prime? number
+ prime_count += 1
+ yield number
+ end
+
+ number += 1
+ end
+ end
+end
+
+
+module DrunkenMathematician
+ module_function
+
+ def prime?(number)
+ return false if number <= 1
+ Math.sqrt(number).to_i.downto(2).each do
+ |i| return false if number % i == 0
+ end
+ end
+
+ def meaningless(n)
+ partitions = RationalSequence.new(n).partition do |rational_number|
+ prime?(rational_number.numerator) || prime?(rational_number.denominator)
+ end
+
+ first_partition_product = partitions[0].reduce(:*) || 1
+ second_partition_product = partitions[1].reduce(:*) || 1
+
+ first_partition_product / second_partition_product
+ end
+
+ def aimless(n)
+ rational_primes = PrimeSequence.new(n).each_slice(2).map do |prime|
+ Rational(prime[0], prime[1] || 1)
+ end
+
+ rational_primes.reduce(:+) || 0
+ end
+
+ def worthless(n)
+ n_fibonacci = FibonacciSequence.new(n).take(n).last || 0
+ max_slice = []
+ max_slice_sum = slice_size = 0
+
+ loop do
+ slice = RationalSequence.new(slice_size)
+ slice_sum = slice.reduce(0, :+)
+
+ break if slice_sum > n_fibonacci
+
+ if max_slice_sum < slice_sum
+ max_slice = slice
+ max_slice_sum = slice_sum
+ end
+
+ slice_size += 1
+ end
+
+ max_slice.to_a
+ end
+end