Fire - Noor

lib/max_subarray.rb

@@ -2,7 +2,18 @@
 # Time Complexity: ?
 # Space Complexity: ?
 def max_sub_array(nums)
-    return 0 if nums == nil
+    return nil if nums.nil?
+
+    max_so_far = nums[0]
+    max_ending_here = nums[0]
+
+    nums.each_with_index do |number, index|
+        if index > 0
+            max_ending_here = [number, max_ending_here + number].max
+            max_so_far = [max_so_far, max_ending_here].max
+        end
+    end
+
+    return max_so_far
 
-    raise NotImplementedError, "Method not implemented yet!"
 end

lib/newman_conway.rb

@@ -1,7 +1,22 @@
 
 
-# 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 if num < 1
+
+  return "1" if num == 1
+
+  results = {}
+  results[1] = 1
+  results[2] = 1
+  n = 3
+
+  while n <= num
+    results[n] = results[results[n-1]] + results[n - results[n - 1]]
+    n += 1
+  end
+
+  return results.values.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]