diff --git a/README.md b/README.md index 8942be93..5ad30028 100644 --- a/README.md +++ b/README.md @@ -737,6 +737,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/). | 2116. Check if a Parentheses String Can Be Valid | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/) | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb) | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb) | | 2121. Intervals Between Identical Elements | [Link](https://leetcode.com/problems/intervals-between-identical-elements/) | [Link](./lib/medium/2121_intervals_between_identical_elements.rb) | [Link](./test/medium/test_2121_intervals_between_identical_elements.rb) | | 2125. Number of Laser Beams in a Bank | [Link](https://leetcode.com/problems/number-of-laser-beams-in-a-bank/) | [Link](./lib/medium/2125_number_of_laser_beams_in_a_bank.rb) | [Link](./test/medium/test_2125_number_of_laser_beams_in_a_bank.rb) | +| 2130. Maximum Twin Sum of a Linked List | [Link](https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/) | [Link](./lib/medium/2130_maximum_twin_sum_of_a_linked_list.rb) | [Link](./test/medium/test_2130_maximum_twin_sum_of_a_linked_list.rb) | | 2425. Bitwise XOR of All Pairings | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/) | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb) | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb) | | 2429. Minimize XOR | [Link](https://leetcode.com/problems/minimize-xor/) | [Link](./lib/medium/2429_minimize_xor.rb) | [Link](./test/medium/test_2429_minimize_xor.rb) | | 2657. Find the Prefix Common Array of Two Arrays | [Link](https://leetcode.com/problems/find-the-prefix-common-array-of-two-arrays/) | [Link](./lib/medium/2657_find_the_prefix_common_array_of_two_arrays.rb) | [Link](./test/medium/test_2657_find_the_prefix_common_array_of_two_arrays.rb) | diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec index ff26e106..3a371cd1 100644 --- a/leetcode-ruby.gemspec +++ b/leetcode-ruby.gemspec @@ -5,7 +5,7 @@ require 'English' ::Gem::Specification.new do |s| s.required_ruby_version = '>= 3.0' s.name = 'leetcode-ruby' - s.version = '9.0.2' + s.version = '9.0.3' s.license = 'MIT' s.files = ::Dir['lib/**/*.rb'] + %w[README.md] s.executable = 'leetcode-ruby' diff --git a/lib/medium/2130_maximum_twin_sum_of_a_linked_list.rb b/lib/medium/2130_maximum_twin_sum_of_a_linked_list.rb new file mode 100644 index 00000000..4201f34b --- /dev/null +++ b/lib/medium/2130_maximum_twin_sum_of_a_linked_list.rb @@ -0,0 +1,38 @@ +# frozen_string_literal: true + +# https://leetcode.com/problems/maximum-twin-sum-of-a-linked-list/ +# @param {ListNode} head +# @return {Integer} +def pair_sum(head) + slow = head + fast = head + first_part = head + + while fast&.next + first_part = slow + slow = slow.next + fast = fast.next.next + end + + prev = nil + + while slow + nxt = slow.next + slow.next = prev + prev = slow + slow = nxt + end + + first_part.next = prev + result = 0 + f = head + s = first_part.next + + while s + result = [result, f.val + s.val].max + f = f.next + s = s.next + end + + result +end diff --git a/test/medium/test_2130_maximum_twin_sum_of_a_linked_list.rb b/test/medium/test_2130_maximum_twin_sum_of_a_linked_list.rb new file mode 100644 index 00000000..74ef9a62 --- /dev/null +++ b/test/medium/test_2130_maximum_twin_sum_of_a_linked_list.rb @@ -0,0 +1,41 @@ +# frozen_string_literal: true + +require_relative '../test_helper' +require_relative '../../lib/common/linked_list' +require_relative '../../lib/medium/2130_maximum_twin_sum_of_a_linked_list' +require 'minitest/autorun' + +class MaximumTwinSumOfALinkedListTest < ::Minitest::Test + def test_default_one + assert_equal( + 6, + pair_sum( + ::ListNode.from_array( + [5, 4, 2, 1] + ) + ) + ) + end + + def test_default_two + assert_equal( + 7, + pair_sum( + ::ListNode.from_array( + [4, 2, 2, 3] + ) + ) + ) + end + + def test_default_three + assert_equal( + 100_001, + pair_sum( + ::ListNode.from_array( + [1, 100_000] + ) + ) + ) + end +end