diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..0051589 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(1) def max_sub_array(nums) return 0 if nums == nil - - raise NotImplementedError, "Method not implemented yet!" + max = nums[0] + max_sum = nums[0] + i = 1 + + while i <= (nums.length - 1) + max = [nums[i], (max + nums[i])].max + max_sum = max if max > max_sum + i += 1 + end + return max_sum end diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..a76476e 100644 --- a/lib/newman_conway.rb +++ b/lib/newman_conway.rb @@ -1,7 +1,26 @@ -# Time complexity: ? -# Space Complexity: ? +# Time complexity: O(n) +# Space Complexity: O(n) +# Resources: https://www.geeksforgeeks.org/newman-conway-sequence/ def newman_conway(num) - raise NotImplementedError, "newman_conway isn't implemented" + raise ArgumentError if num < 1 + return "1" if num == 1 + return "1 1" if num == 2 + + array = Array.new(num, 0) + i = 1 + + while i <= num + if i == 1 || i == 2 + array[i] = 1 + else + array[i] = array[array[i - 1]] + array[i - array[i-1]] + end + i += 1 + end + + array.shift # remove first element + + 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]