Kang's interview

string = "Oversee.NET"
counter = 1
string.chars.map do |ch|
  case counter % 3
  when 0 then 
    ch.upcase!
  else
    ch.downcase!
  end
  counter += 1 if ch.match(/\w/)
  ch
end.join("")



array = (-50..50).to_a.product (-50..50).to_a
p array 
array1 = array.select do |e|
  e.first + e.last == 10
end
p array1

array2 = array1.map do |e|
  e.sort
end
p array2

array3 = array2.uniq
p array3