Sara - Branches

lib/max_subarray.rb

@@ -1,8 +1,22 @@
 
-# Time Complexity: ?
-# Space Complexity: ?
+# Time Complexity: o(n)
+# Space Complexity: o(1)
 def max_sub_array(nums)
+    # raise NotImplementedError, "Method not implemented yet!"
     return 0 if nums == nil
-
-    raise NotImplementedError, "Method not implemented yet!"
+    return nil if nums == []
+    array_max = 0
+    current_max = 0
+
+    nums.each do |num|
+        array_max = array_max + num
+        array_max = array_max < 0 ? 0 : array_max
+        if array_max > current_max
+            current_max = array_max
+        end
+    end
+    if current_max == 0
+        current_max = nums.max
+    end
+    return current_max
 end

lib/newman_conway.rb

@@ -1,7 +1,19 @@
 
 
-# Time complexity: ?
-# Space Complexity: ?
+# Time complexity: o(n)
+# Space Complexity: o(n)
 def newman_conway(num)
-  raise NotImplementedError, "newman_conway isn't implemented"
+  # raise NotImplementedError, "newman_conway isn't implemented"
+  raise ArgumentError if num < 1
+  return "1" if num == 1
+  array = [1, 1]
+  i = 2
+
+  until i == num
+    previous = array[i - 1]
+    current = array[previous - 1] + array [i - previous]
+    array << current
+    i += 1
+  end
+  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]