Same.rb

=begin

Given two arrays a and b write a function comp(a, b) (compSame(a, b) in Clojure)
that checks whether the two arrays have the "same" elements, with the same
multiplicities. "Same" means, here, that the elements in b are the elements
in a squared, regardless of the order.

Examples

Valid arrays

a = [121, 144, 19, 161, 19, 144, 19, 11]
b = [121, 14641, 20736, 361, 25921, 361, 20736, 361]
comp(a, b) returns true because in b 121 is the square of 11, 14641 is the
square of 121, 20736 the square of 144, 361 the square of 19, 25921 the square
of 161, and so on. It gets obvious if we write b's elements in terms of squares:

a = [121, 144, 19, 161, 19, 144, 19, 11]
b = [11*11, 121*121, 144*144, 19*19, 161*161, 19*19, 144*144, 19*19]
Invalid arrays

If we change the first number to something else, comp may not return true anymore

a = [121, 144, 19, 161, 19, 144, 19, 11]
b = [132, 14641, 20736, 361, 25921, 361, 20736, 361]
comp(a,b) returns false because in b 132 is not the square of any number of a.

a = [121, 144, 19, 161, 19, 144, 19, 11]
b = [121, 14641, 20736, 36100, 25921, 361, 20736, 361]
comp(a,b) returns false because in b 36100 is not the square of any number of a.

=end

# My Solution
def comp(array1, array2)
  return false if array1 == nil || array2 == nil
  result = false

  array2.sort!.map {|x| x}
  array1.sort!.each_with_index {|x,i| result = true if x*x != array2[i]}
  return !result
end

# Better Solution
def comp(array1, array2)
  array1.nil? || array2.nil? ? false : array1.sort.map {|v| v ** 2} == array2.sort
end

# Another Solution
def comp(array1, array2)
  return false if array1.nil? || array2.nil?
  array1.map {|num| num ** 2}.sort == array2.sort
end