implement newman_conway

Author: geneminde

lib/newman_conway.rb

@@ -1,7 +1,15 @@
-
-
-# Time complexity: ?
-# Space Complexity: ?
+# Time complexity: O(n)
+# Space Complexity: O(n)
 def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
+  raise ArgumentError.new("Input must be an integer greater than zero") if num < 1
+  return "1" if num == 1
+  nums = {}
+  nums[1] = 1
+  nums[2] = 1
+  n = 3
+  while n <= num
+    nums[n] = nums[nums[n - 1]] + nums[n - nums[n - 1]]
+    n += 1
+  end
+  return nums.values.join(" ")
 end