Branches - Monick

lib/max_subarray.rb

@@ -2,7 +2,27 @@
 # Time Complexity: ?
 # Space Complexity: ?
 def max_sub_array(nums)
-    return 0 if nums == nil
-
-    raise NotImplementedError, "Method not implemented yet!"
+    return nil if nums == []
+    return nums[0] if nums.length == 1
+
+    # start at first item in array
+    max_so_far = nums[0]
+    max_ending_here = 0
+
+    nums.each do |i|
+        # extend subarray and get it's total
+        max_ending_here = max_ending_here + i
+        # if new total is less than value of just i
+        if max_ending_here < i
+            # set new subtoal to index value
+            max_ending_here = i
+        end 
+        #  if new total is greater than value of just i
+        if max_so_far < max_ending_here
+            # set current total to subarray total
+            max_so_far = max_ending_here
+        end 
+    end 
+
+    return max_so_far
 end

lib/newman_conway.rb

@@ -1,7 +1,20 @@
 
 
-# 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 == 0 
+  results = []
+
+  i = 1
+  while i <= num
+    if i < 3
+      results[i] = 1
+    else 
+      results[i] = results[results[i - 1]] + results[i - results[i - 1]]
+    end 
+    i += 1 
+  end 
+
+  return results.join(" ").lstrip.encode("UTF-8", "US-ASCII")
 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]