un abridged code.rb

un_abridged_code.rb

def binary_search(item,array,min = 0,max = array.length, half = (min + max) / 2)
  return min if item == array[min]
  return -1 if (item < array[0] || item > array[array.length-1]) || (min == max - 1)
  item < array[half] ? binary_search(item,array,min,half) : binary_search(item,array,half,array.length)
end

def prime_factors(n, factors = [], f = 2)
  return factors.push(f) if n == f
  n % f == 0 ? prime_factors(n / f, factors.push(f)) : prime_factors(n, factors, f + 1)
end

def is_fibonacci?(i)
  a,b=0,1
    until b >= i
        a,b=b,a+b
        return true if b == i
    end
end