2025-02-28 v. 8.7.7: added "1679. Max Number of K-Sum Pairs"

Author: fartem

README.md

@@ -710,6 +710,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1641. Count Sorted Vowel Strings                                                    | [Link](https://leetcode.com/problems/count-sorted-vowel-strings/)                                                    | [Link](./lib/medium/1641_count_sorted_vowel_strings.rb)                                                    | [Link](./test/medium/test_1641_count_sorted_vowel_strings.rb)                                                    |
 | 1669. Merge In Between Linked Lists                                                 | [Link](https://leetcode.com/problems/merge-in-between-linked-lists/)                                                 | [Link](./lib/medium/1669_merge_in_between_linked_lists.rb)                                                 | [Link](./test/medium/test_1669_merge_in_between_linked_lists.rb)                                                 |
 | 1670. Design Front Middle Back Queue                                                | [Link](https://leetcode.com/problems/design-front-middle-back-queue/)                                                | [Link](./lib/medium/1670_design_front_middle_back_queue.rb)                                                | [Link](./test/medium/test_1670_design_front_middle_back_queue.rb)                                                |
+| 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)                                                     |
 | 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)                                                                  |

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 = '8.7.6'
+  s.version = '8.7.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/1679_max_number_of_k_sum_pairs.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/max-number-of-k-sum-pairs/
+# @param {Integer[]} nums
+# @param {Integer} k
+# @return {Integer}
+def max_operations(nums, k)
+  count = {}
+  result = 0
+
+  nums.each do |num|
+    s = k - num
+    s_count = count.fetch(s, 0)
+
+    if s_count.positive?
+      result += 1
+      count[s] = s_count - 1
+    else
+      count[num] = count.fetch(num, 0) + 1
+    end
+  end
+
+  result
+end

test/medium/test_1679_max_number_of_k_sum_pairs.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/1679_max_number_of_k_sum_pairs'
+require 'minitest/autorun'
+
+class MaxNumberOfKSumPairsTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      2,
+      max_operations(
+        [1, 2, 3, 4],
+        5
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      1,
+      max_operations(
+        [3, 1, 3, 4, 3],
+        6
+      )
+    )
+  end
+end