diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..9412881 100644 --- a/lib/max_subarray.rb +++ b/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 diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..9301454 100644 --- a/lib/newman_conway.rb +++ b/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 \ 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]