Time - Denisse

lib/max_subarray.rb

@@ -1,8 +1,16 @@
 
-# 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!"
+    max = nums[0]
+    max_sum = nums[0]
+    i = 1
+
+    while i <= (nums.length - 1)
+        max = [nums[i], (max + nums[i])].max
+        max_sum = max if max > max_sum
+        i += 1
+    end
+    return max_sum
 end

lib/newman_conway.rb

@@ -1,7 +1,26 @@
 
 
-# Time complexity: ?
-# Space Complexity: ?
+# Time complexity: O(n)
+# Space Complexity: O(n)
+# Resources: https://www.geeksforgeeks.org/newman-conway-sequence/
 def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
+  raise ArgumentError if num < 1
+  return "1" if num == 1
+  return "1 1" if num == 2
+
+  array = Array.new(num, 0)
+  i = 1
+
+  while i <= num 
+    if i == 1 || i == 2
+      array[i] = 1
+    else
+      array[i] = array[array[i - 1]] + array[i - array[i-1]]
+    end
+    i += 1
+  end
+
+  array.shift # remove first element
+
+  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]