input

3 7

Rabbit.rb

class Rabbit

  @@result = 0
  @@hsh = {}

  def initialize(path = "./input")
    File.open(path, "r") do |file|  
      file.each_line do |line|
        line = line.split
        short_path(line[0].to_i, line[1].to_i)
      end
    end
  end  

private 

  def short_path(jump, total)
    optimal_jumps = []
    while total >= jump do
      total -= jump
      optimal_jumps << jump
    end
    optimal_jumps << total if total > 0
    melt(optimal_jumps)
    puts @@result
  end


  def melt(numbers)
    combinations(numbers)
    arr_numbers = []
    numbers.each { |val| arr_numbers << ([] << val)}
    arr_numbers.each_index do |index|
      if arr_numbers[index][0] > 1 && arr_numbers[index][0] > arr_numbers[index][1].to_i
        arr_numbers[index][0] -= 1
        arr_numbers[index][1] == nil ? arr_numbers[index][1] = 1 : arr_numbers[index][1] += 1
        if @@hsh[arr_numbers.flatten] == nil
          @@hsh[arr_numbers.flatten] = 1
          melt(arr_numbers.flatten)
        end  
      end   
    end 
  end


  def combinations(jumps)
    same = {}
    factorial_arr = []  
    jumps.each { |jump| same[jump] == nil ? same[jump] = 1 : same[jump] += 1 }
    n = (1..jumps.count).inject(1, :*)
    same.values.each { |value| factorial_arr << (1..value).inject(1, :*) }
    r = factorial_arr.inject(:*)
    @@result += (n / r)
  end   

end

Rabbit.new