From 6999b30b2992450345d94af7d82e89361ba486c3 Mon Sep 17 00:00:00 2001 From: Julia Bouvier Date: Sun, 29 Mar 2020 14:40:30 -0700 Subject: [PATCH 1/2] Implemented newman_conway --- lib/newman_conway.rb | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/lib/newman_conway.rb b/lib/newman_conway.rb index 4c985cd..01ea003 100644 --- a/lib/newman_conway.rb +++ b/lib/newman_conway.rb @@ -1,7 +1,21 @@ -# 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 < 1 + + storage = [] + + i = 1 + while i <= num + if i < 3 + storage[i] = 1 + else + storage[i] = storage[storage[i - 1]] + storage[i - storage[i - 1]] + end + i += 1 + end + + return storage.join(" ")[1..-1] # fencepost slice end \ No newline at end of file From 242b3df6059902e357cfbfc5c813718d6e9fac67 Mon Sep 17 00:00:00 2001 From: Julia Bouvier Date: Sun, 29 Mar 2020 16:31:11 -0700 Subject: [PATCH 2/2] Implemented max_sub_array --- lib/max_subarray.rb | 21 ++++++++++++++++++--- test/max_sub_array_test.rb | 2 +- 2 files changed, 19 insertions(+), 4 deletions(-) diff --git a/lib/max_subarray.rb b/lib/max_subarray.rb index 5204edb..be28b72 100644 --- a/lib/max_subarray.rb +++ b/lib/max_subarray.rb @@ -2,7 +2,22 @@ # Time Complexity: ? # Space Complexity: ? 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.empty? + + max_so_far = max_ending_here = nums[0] + + nums[1..-1].each do |num| + if num > max_ending_here + num + max_ending_here = num + else + max_ending_here += num + end + + if max_so_far < max_ending_here + max_so_far = max_ending_here + end + end + + return max_so_far 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]