Solution to tutorial 1, q2

gistfile1.rb

# this is the O(n) solution for tutorial 1, question 2 in ruby

A = [2,4,6,8] # elements to multiply

B = [] # left products
C = [] # right products

output = [] # to hold final result

product = 1
A.each_with_index {|x, y| B[y] = product; product *= A[y]}

product = 1
A.each_with_index {|x, y| C[A.length-y-1] = product; product *= A[A.length-y-1]}

A.each_with_index {|x, y| output[y] = B[y] * C[y]}

puts(output);