Janice H.

lib/max_subarray.rb

@@ -1,8 +1,19 @@
 
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: O(n)
+# Space Complexity: O(1)
 def max_sub_array(nums)
-    return 0 if nums == nil
-
-    raise NotImplementedError, "Method not implemented yet!"
+	return 0 if nums == nil
+	return nil if nums == []
+	return nums[0] if nums.length == 1
+	local_max = 0
+	global_max = -Float::INFINITY
+	index = 0
+	while index < nums.length
+		local_max = [nums[index], local_max + nums[index]].max
+		if local_max > global_max
+			global_max = local_max
+		end
+		index += 1
+	end
+	return global_max
 end

lib/newman_conway.rb

@@ -1,7 +1,18 @@
 
 
-# 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, "Number must be greater than zero!" if num < 1
+  return "1" if num == 1
+  return "1 1" if num == 2
+  array = [0, 1, 1]
+  index = 3
+  until index == num + 1
+    new_num = array[array[index - 1]] + array[index - (array[index - 1])]
+    array << new_num
+    index += 1
+  end
+  array.shift
+  return array.join(" ")
 end

test/max_sub_array_test.rb

@@ -1,6 +1,6 @@
 require_relative "test_helper"
 
-xdescribe "max subarray" do
+describe "max subarray" do
   it "will work for [-2,1,-3,4,-1,2,1,-5,4]" do
     # Arrange
     input = [-2,1,-3,4,-1,2,1,-5,4]