Time - Jocelyn

lib/max_subarray.rb

@@ -1,8 +1,23 @@
 
-# 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 nums.inject(:+) if nums.length <= 3
+
+    max_so_far = nums[0]
+    max_ending_here = nums[0]
+
+    nums.each do |num|
+      if max_ending_here < num
+        max_ending_here = num
+      elsif num < max_ending_here
+        max_ending_here += num
+      end
+
+      if max_so_far < max_ending_here
+        max_so_far = max_ending_here
+      end
+    end
+
+    return max_so_far
 end

lib/newman_conway.rb

@@ -1,7 +1,22 @@
+# Time complexity: O(n)
+# Space Complexity: O(n)
+def newman_conway(num)
+  raise ArgumentError if num == 0
+  array = [num, 0]
 
+  count = 1
+
+  until count > num
+    if count == 1 || count == 2
+      array[count] = 1
+    else
+      array[count] = array[array[count - 1]] + array[count - array[count - 1]]
+    end
+
+    count += 1
+  end
 
-# Time complexity: ?
-# Space Complexity: ?
-def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
+  p array[1..(array.length - 1)].join(' ')
+
+  array[1..(array.length - 1)].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]