diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..1bee875 100644 --- a/lib/max_subarray.rb +++ b/lib/max_subarray.rb @@ -1,8 +1,18 @@ -# 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 nil if nums.nil? || nums.empty? + + max_so_far = nums[0] + max_ending_here = nums[0] + i = 1 + + while i < nums.length + max_ending_here = [nums[i], (max_ending_here + nums[i])].max + max_so_far = [max_so_far, max_ending_here].max + i += 1 + end + + return max_so_far end diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..f8840dc 100644 --- a/lib/newman_conway.rb +++ b/lib/newman_conway.rb @@ -1,7 +1,25 @@ -# Time complexity: ? -# Space Complexity: ? +# Time complexity: O(n) +# Space Complexity: O(n) def newman_conway(num) - raise NotImplementedError, "newman_conway isn't implemented" + s = [0, 1, 1] + i = 3 + + if num == 0 + raise ArgumentError, "Number should be greater or equal to 1" + elsif num == 1 + return "1" + elsif num == 2 + return "1 1" + else + while i <= num + s[i] = s[s[i - 1]] + s[i - s[i - 1]] + i += 1 + end + end + # remove first element and return the sequence as string + + return s.drop(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]