From b854c175dc356649dbc1c30401121ef8e8cc644e Mon Sep 17 00:00:00 2001 From: fartem Date: Tue, 4 Mar 2025 09:39:12 +0300 Subject: [PATCH] 2025-03-04 v. 8.8.0: added "1721. Swapping Nodes in a Linked List" --- README.md | 1 + leetcode-ruby.gemspec | 2 +- lib/common/linked_list.rb | 2 +- .../1721_swapping_nodes_in_a_linked_list.rb | 24 +++++++++++ ...st_1721_swapping_nodes_in_a_linked_list.rb | 40 +++++++++++++++++++ 5 files changed, 67 insertions(+), 2 deletions(-) create mode 100644 lib/medium/1721_swapping_nodes_in_a_linked_list.rb create mode 100644 test/medium/test_1721_swapping_nodes_in_a_linked_list.rb diff --git a/README.md b/README.md index adbfc391..615a819e 100644 --- a/README.md +++ b/README.md @@ -713,6 +713,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/). | 1679. Max Number of K-Sum Pairs | [Link](https://leetcode.com/problems/max-number-of-k-sum-pairs/) | [Link](./lib/medium/1679_max_number_of_k_sum_pairs.rb) | [Link](./test/medium/test_1679_max_number_of_k_sum_pairs.rb) | | 1685. Sum of Absolute Differences in a Sorted Array | [Link](https://leetcode.com/problems/sum-of-absolute-differences-in-a-sorted-array/) | [Link](./lib/medium/1685_sum_of_absolute_differences_in_a_sorted_array.rb) | [Link](./test/medium/test_1685_sum_of_absolute_differences_in_a_sorted_array.rb) | | 1706. Where Will the Ball Fall | [Link](https://leetcode.com/problems/where-will-the-ball-fall/) | [Link](./lib/medium/1706_where_will_the_ball_fall.rb) | [Link](./test/medium/test_1706_where_will_the_ball_fall.rb) | +| 1721. Swapping Nodes in a Linked List | [Link](https://leetcode.com/problems/swapping-nodes-in-a-linked-list/) | [Link](./lib/medium/1721_swapping_nodes_in_a_linked_list.rb) | [Link](./test/medium/test_1721_swapping_nodes_in_a_linked_list.rb) | | 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) | | 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) | diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec index 3bfa0af0..a076c652 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 = '8.7.9' + s.version = '8.8.0' s.license = 'MIT' s.files = ::Dir['lib/**/*.rb'] + %w[README.md] s.executable = 'leetcode-ruby' diff --git a/lib/common/linked_list.rb b/lib/common/linked_list.rb index 333f1ced..e3ac09d3 100644 --- a/lib/common/linked_list.rb +++ b/lib/common/linked_list.rb @@ -11,7 +11,7 @@ def initialize(val = 0, nxt = nil) @next = nxt end - # @param {Array} values + # @param {ListNode} values def self.from_array(values) return if values.empty? diff --git a/lib/medium/1721_swapping_nodes_in_a_linked_list.rb b/lib/medium/1721_swapping_nodes_in_a_linked_list.rb new file mode 100644 index 00000000..454c3d63 --- /dev/null +++ b/lib/medium/1721_swapping_nodes_in_a_linked_list.rb @@ -0,0 +1,24 @@ +# frozen_string_literal: true + +# https://leetcode.com/problems/swapping-nodes-in-a-linked-list/ +# @param {ListNode} head +# @param {Integer} k +# @return {ListNode} +def swap_nodes(head, k) + nodes = [] + pointer = head + + while pointer + nodes << pointer + + pointer = pointer.next + end + + first = nodes[k - 1] + second = nodes[nodes.size - k] + temp = first.val + first.val = second.val + second.val = temp + + head +end diff --git a/test/medium/test_1721_swapping_nodes_in_a_linked_list.rb b/test/medium/test_1721_swapping_nodes_in_a_linked_list.rb new file mode 100644 index 00000000..6109e894 --- /dev/null +++ b/test/medium/test_1721_swapping_nodes_in_a_linked_list.rb @@ -0,0 +1,40 @@ +# frozen_string_literal: true + +require_relative '../test_helper' +require_relative '../../lib/common/linked_list' +require_relative '../../lib/medium/1721_swapping_nodes_in_a_linked_list' +require 'minitest/autorun' + +class SwappingNodesInALindedListTest < ::Minitest::Test + def test_default_one + assert( + ::ListNode.are_equals( + ::ListNode.from_array( + [1, 4, 3, 2, 5] + ), + swap_nodes( + ::ListNode.from_array( + [1, 2, 3, 4, 5] + ), + 2 + ) + ) + ) + end + + def test_default_two + assert( + ::ListNode.are_equals( + ::ListNode.from_array( + [7, 9, 6, 6, 8, 7, 3, 0, 9, 5] + ), + swap_nodes( + ::ListNode.from_array( + [7, 9, 6, 6, 7, 8, 3, 0, 9, 5] + ), + 5 + ) + ) + ) + end +end