Cue Challenge answers

cue1.rb

s = File.open("gettysburg.txt").read().downcase

maxrange = s.length

matched = {}

for range in (2..maxrange) 
  (matched["#{range}"] ||= []) << (0..s.length - 1).find_all { |i| s[i,range] == s[i,range].reverse }
end

matched.delete_if { |key,value| value.last.length < 2 }

#output shows text position 204 with length 7

s[204,7]

cue2.rb

require 'prime'

def is_divisor?(x,i)
  if x % i == 0
		return true
	else
		return false
	end
end

def fib_prime_over(x)
	i1,i2 = 1,1
	while i1 < x
		i1,i2 = i2, i2+i1
	end
	until i2.prime?
		i1,i2 = i2, i2+i1
	end
	return i2
end

def add_prime_divisors(x)
	divisors = []
	for i in 2..x
		if i.prime? && is_divisor?(x,i)
			divisors.push(i)
		end
	end
	divisors.inject(:+)
end

step1 = fib_prime_over(227000)
puts step1
step2 = step1+1
answer = add_prime_divisors(step2)
puts answer

cue3.rb

#For an individual subset,
#
#1. Remove elements (number of elements between 0 and size-3)
#2. Set sum equal to the largest number (largest number is the last one in a sorted array).
#3. Add up the rest of the numbers and check to see if it's equal to a sum
#4. If it's equal, put it in an array

#Then add up the number subsets in the array
#
#This code also reads the file in and coverts the numbers, initially strings in an array, to integers in an array
#This is so I can work with it later
#

require 'csv'

subsets = 0
combos_to_remove = []
string_numbers = CSV.read("numbers.csv").last.each { |element| element.strip! }
numbers = []
string_numbers.each do |number|
  numbers.push(number.to_i)
end
max_to_remove = numbers.length - 3

for i in 1..max_to_remove
	combos_to_remove.push(numbers.combination(i).to_a)
end

combos_to_remove.flatten!(1)

combos_to_remove.each do |combo|
	temparray = numbers.dup
	temparray = temparray - combo
	last_element = temparray.sort.last
	temparray.delete(last_element)
	if temparray.inject(:+) == last_element
		subsets += 1
	end
end

puts subsets