2025-02-25 v. 8.7.0: added "1530. Number of Good Leaf Nodes Pairs"

Author: fartem

README.md

@@ -703,6 +703,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1504. Count Submatrices With All Ones                                               | [Link](https://leetcode.com/problems/count-submatrices-with-all-ones/)                                               | [Link](./lib/medium/1504_count_submatrices_with_all_ones.rb)                                               | [Link](./test/medium/test_1504_count_submatrices_with_all_ones.rb)                                               |
 | 1525. Number of Good Ways to Split a String                                         | [Link](https://leetcode.com/problems/number-of-good-ways-to-split-a-string/)                                         | [Link](./lib/medium/1525_number_of_good_ways_to_split_a_string.rb)                                         | [Link](./test/medium/test_1525_number_of_good_ways_to_split_a_string.rb)                                         |
 | 1529. Minimum Suffix Flips                                                          | [Link](https://leetcode.com/problems/minimum-suffix-flips/)                                                          | [Link](./lib/medium/1529_minimum_suffix_flips.rb)                                                          | [Link](./test/medium/test_1529_minimum_suffix_flips.rb)                                                          |
+| 1530. Number of Good Leaf Nodes Pairs                                               | [Link](https://leetcode.com/problems/number-of-good-leaf-nodes-pairs/)                                               | [Link](./lib/medium/1530_number_of_good_leaf_nodes_pairs.rb)                                               | [Link](./test/medium/test_1530_number_of_good_leaf_nodes_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 = '8.6.9'
+  s.version = '8.7.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/1530_number_of_good_leaf_nodes_pairs.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/number-of-good-leaf-nodes-pairs/
+# @param {TreeNode} root
+# @param {Integer} distance
+# @return {Integer}
+def count_good_pairs(root, distance)
+  @result = 0
+  calculate_for_count_pairs(root, distance)
+
+  @result
+end
+
+private
+
+# @param {TreeNode} root
+# @param {Integer} distance
+# @return {Integer[]}
+def calculate_for_count_pairs(node, distance)
+  return [] unless node
+
+  return [1] if !node.left && !node.right
+
+  left = calculate_for_count_pairs(node.left, distance)
+  right = calculate_for_count_pairs(node.right, distance)
+
+  left.each do |l|
+    right.each do |r|
+      @result += 1 if l + r <= distance
+    end
+  end
+
+  path = []
+
+  left.each { |l| path << l + 1 if l + 1 < distance }
+
+  right.each { |r| path << r + 1 if r + 1 < distance }
+
+  path
+end

test/medium/test_1530_number_of_good_leaf_nodes_pairs.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/1530_number_of_good_leaf_nodes_pairs'
+require 'minitest/autorun'
+
+class NumberOfGoodLeafNodesPairsTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      1,
+      count_good_pairs(
+        ::TreeNode.build_tree(
+          [1, 2, 3, nil, 4]
+        ),
+        3
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      2,
+      count_good_pairs(
+        ::TreeNode.build_tree(
+          [1, 2, 3, 4, 5, 6, 7]
+        ),
+        3
+      )
+    )
+  end
+
+  def test_default_three
+    assert_equal(
+      1,
+      count_good_pairs(
+        ::TreeNode.build_tree(
+          [7, 1, 4, 6, nil, 5, 3, nil, nil, nil, nil, nil, 2]
+        ),
+        3
+      )
+    )
+  end
+end