From 0fca2c468fa5b6f4228e215cd6c7b99554c61d40 Mon Sep 17 00:00:00 2001 From: Amal Hassan-Ali Date: Sat, 28 Mar 2020 14:13:02 -0700 Subject: [PATCH 1/2] completed all methods --- lib/max_subarray.rb | 20 +++++++++++++++----- lib/newman_conway.rb | 21 +++++++++++++++++---- test/max_sub_array_test.rb | 2 +- 3 files changed, 33 insertions(+), 10 deletions(-) diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..d84e78a 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(n) def max_sub_array(nums) - return 0 if nums == nil - - raise NotImplementedError, "Method not implemented yet!" + return nil if nums.empty? + max = nums[0] + curr_max = 0 + + nums.each do |num| + if num > num + curr_max + curr_max = num + elsif num + curr_max >= num + curr_max = num + curr_max + end + max = curr_max if curr_max > max + end + return max end diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..fa07823 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" -end \ No newline at end of file + raise ArgumentError if num < 1 + return "1" if num == 1 + return "1 1" if num == 2 + res = "1 1" + curr = 3 + num_arr = [0,1,1] + while curr <= num + num_arr[curr] = num_arr[num_arr[curr - 1]] + num_arr[curr - num_arr[curr - 1]] + res += " #{num_arr[curr]}" + curr += 1 + end + return res +end + + 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] From cd8778048664fb128219b189df226af3681ed310 Mon Sep 17 00:00:00 2001 From: Amal Hassan-Ali Date: Sat, 28 Mar 2020 14:19:15 -0700 Subject: [PATCH 2/2] changed complexity --- lib/max_subarray.rb | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index d84e78a..47dd936 100644 --- a/lib/max_subarray.rb +++ b/lib/max_subarray.rb @@ -1,6 +1,6 @@ # Time Complexity: o(n) -# Space Complexity: o(n) +# Space Complexity: o(1) def max_sub_array(nums) return nil if nums.empty? max = nums[0]