diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..c59db98 100644 --- a/lib/max_subarray.rb +++ b/lib/max_subarray.rb @@ -1,8 +1,19 @@ -# 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 0 if nums == nil + return nil if nums == [] + return nums[0] if nums.length == 1 + local_max = 0 + global_max = -Float::INFINITY + index = 0 + while index < nums.length + local_max = [nums[index], local_max + nums[index]].max + if local_max > global_max + global_max = local_max + end + index += 1 + end + return global_max end diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..5778063 100644 --- a/lib/newman_conway.rb +++ b/lib/newman_conway.rb @@ -1,7 +1,18 @@ -# 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, "Number must be greater than zero!" if num < 1 + return "1" if num == 1 + return "1 1" if num == 2 + array = [0, 1, 1] + index = 3 + until index == num + 1 + new_num = array[array[index - 1]] + array[index - (array[index - 1])] + array << new_num + index += 1 + end + array.shift + return array.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]