Merge pull request #775 from fartem/437_Path_Sum_III

2024-11-18 v. 7.0.5: fixed "437. Path Sum III"

Author: fartem

README.md

@@ -570,3 +570,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 424. Longest Repeating Character Replacement                    | [Link](https://leetcode.com/problems/longest-repeating-character-replacement/)                    | [Link](./lib/medium/424_longest_repeating_character_replacement.rb)                    | [Link](./test/medium/test_424_longest_repeating_character_replacement.rb)                    |
 | 429. N-ary Tree Level Order Traversal                           | [Link](https://leetcode.com/problems/n-ary-tree-level-order-traversal/)                           | [Link](./lib/medium/429_n_ary_tree_level_order_traversal.rb)                           | [Link](./test/medium/test_429_n_ary_tree_level_order_traversal.rb)                           |
 | 435. Non-overlapping Intervals                                  | [Link](https://leetcode.com/problems/non-overlapping-intervals/)                                  | [Link](./lib/medium/435_non_overlapping_intervals.rb)                                  | [Link](./test/medium/test_435_non_overlapping_intervals.rb)                                  |
+| 437. Path Sum III                                               | [Link](https://leetcode.com/problems/path-sum-iii/)                                               | [Link](./lib/medium/437_path_sum_iii.rb)                                               | [Link](./test/medium/test_437_path_sum_iii.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 = '7.0.4'
+  s.version = '7.0.5'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/437_path_sum_iii.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/path-sum-iii/
+# @param {TreeNode} root
+# @param {Integer} target_sum
+# @return {Integer}
+def path_sum437(root, target_sum)
+  return 0 unless root
+
+  traverse437(root, target_sum) + path_sum437(root.left, target_sum) + path_sum437(root.right, target_sum)
+end
+
+private
+
+# @param {TreeNode} node
+# @param {Integer} target_sum
+# @return {Integer}
+def traverse437(node, target_sum)
+  return 0 unless node
+
+  result = target_sum == node.val ? 1 : 0
+  result += traverse437(node.left, target_sum - node.val)
+  result += traverse437(node.right, target_sum - node.val)
+
+  result
+end

test/medium/test_437_path_sum_iii.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/437_path_sum_iii'
+require 'minitest/autorun'
+
+class PathSumIIITest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      3,
+      path_sum437(
+        ::TreeNode.new(
+          10,
+          ::TreeNode.new(
+            5,
+            ::TreeNode.new(
+              3,
+              ::TreeNode.new(3),
+              ::TreeNode.new(-2)
+            ),
+            ::TreeNode.new(
+              2,
+              nil,
+              ::TreeNode.new(1)
+            )
+          ),
+          ::TreeNode.new(
+            -3,
+            ::TreeNode.new(11),
+            nil
+          )
+        ),
+        8
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      3,
+      path_sum437(
+        ::TreeNode.new(
+          5,
+          ::TreeNode.new(
+            4,
+            ::TreeNode.new(
+              11,
+              ::TreeNode.new(7),
+              ::TreeNode.new(2)
+            ),
+            nil
+          ),
+          ::TreeNode.new(
+            8,
+            ::TreeNode.new(13),
+            ::TreeNode.new(
+              4,
+              ::TreeNode.new(5),
+              ::TreeNode.new(1)
+            )
+          )
+        ),
+        22
+      )
+    )
+  end
+end