diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..ea396e6 100644 --- a/lib/max_subarray.rb +++ b/lib/max_subarray.rb @@ -1,8 +1,16 @@ -# Time Complexity: ? -# Space Complexity: ? + +# Time Complexity: O(n) +# Space Complexity: O(n) def max_sub_array(nums) return 0 if nums == nil - - raise NotImplementedError, "Method not implemented yet!" + max_ending_here = nums[0] + max_so_far = nums[0] + + for i in (1..nums.length - 1 ) do + max_ending_here = [nums[i], max_ending_here + nums[i]].max + max_so_far = [max_so_far, max_ending_here].max + end + return max_so_far + end diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..1a3b405 100644 --- a/lib/newman_conway.rb +++ b/lib/newman_conway.rb @@ -1,7 +1,22 @@ -# Time complexity: ? -# Space Complexity: ? +# Time complexity: O(n) +# Space Complexity: O(n) + +# P(n) = P(P(n - 1)) + P(n - P(n - 1) def newman_conway(num) - raise NotImplementedError, "newman_conway isn't implemented" + if num < 1 + raise ArgumentError.new + end + + return "1" if num == 1 + return "1 1" if num == 2 + result = [0,1,1] + + for i in (3..num) do + answer = result[result[i - 1]] + result[i - result[i - 1]] + result.append(answer) + end + + return result[1,result.length - 1].join(" ") end \ No newline at end of file diff --git a/test/max_sub_array_test.rb b/test/max_sub_array_test.rb index 3253cdf..e27e1ca 100644 --- a/test/max_sub_array_test.rb +++ b/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]