From c6f2555e5e52276954285b82294f4d876d2ebc9a Mon Sep 17 00:00:00 2001
From: charlottea <charlottea@allenai.org>
Date: Sun, 18 Oct 2020 19:48:46 -0700
Subject: [PATCH] implement methods and pass tests

---
 lib/max_subarray.rb  | 20 ++++++++++++++++----
 lib/newman_conway.rb | 17 +++++++++++++----
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb
index 5204edb..15ea5b9 100644
--- a/lib/max_subarray.rb
+++ b/lib/max_subarray.rb
@@ -1,8 +1,20 @@
 
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: O(n)
+# Space Complexity: O(1)
 def max_sub_array(nums)
-    return 0 if nums == nil
+    return nil if nums.nil? || nums.empty?
     
-    raise NotImplementedError, "Method not implemented yet!"
+    max_so_far = nums[0]
+    max_ending_here = nums[0]
+
+    i = 1
+    while i < nums.length
+      max_ending_here += nums[i]
+      # assign max to current num if max_ending_here is less than nums[i]
+      max_ending_here = nums[i] if max_ending_here < nums[i]
+      max_so_far = max_ending_here if max_so_far < max_ending_here
+      i += 1
+    end
+
+    return max_so_far
 end
diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb
index 4c985cd..eb4c36a 100644
--- a/lib/newman_conway.rb
+++ b/lib/newman_conway.rb
@@ -1,7 +1,16 @@
+# Time complexity: o(n)
+# Space Complexity: o(n)
+def newman_conway(num)
+  raise ArgumentError if num <= 0
+  return "1" if num == 1
+  return "1 1" if num == 2
 
+  array = [0, 1, 1]
+  i = 3
+  while i <= num
+    array[i] = array[array[i - 1]] + array[i - array[i - 1]]
+    i += 1
+  end
 
-# Time complexity: ?
-# Space Complexity: ?
-def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
+  return array[1..-1].join(" ")
 end
\ No newline at end of file