From 00b8c2579af7387675f6d3a1481b755f851f20e8 Mon Sep 17 00:00:00 2001
From: fartem <jaman.smlnsk@gmail.com>
Date: Fri, 17 Jan 2025 11:14:32 +0300
Subject: [PATCH] 2025-01-17 v. 8.1.5: added "979. Distribute Coins in Binary
 Tree"

---
 README.md                                     |  1 +
 leetcode-ruby.gemspec                         |  2 +-
 .../979_distribute_coins_in_binary_tree.rb    | 26 ++++++++++++++
 ...est_979_distribute_coins_in_binary_tree.rb | 34 +++++++++++++++++++
 4 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 lib/medium/979_distribute_coins_in_binary_tree.rb
 create mode 100644 test/medium/test_979_distribute_coins_in_binary_tree.rb

diff --git a/README.md b/README.md
index 9297ccc6..64ba4c6a 100644
--- a/README.md
+++ b/README.md
@@ -649,6 +649,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 958. Check Completeness of a Binary Tree                         | [Link](https://leetcode.com/problems/check-completeness-of-a-binary-tree/)                         | [Link](./lib/medium/958_check_completeness_of_a_binary_tree.rb)                         | [Link](./test/medium/test_958_check_completeness_of_a_binary_tree.rb)                         |
 | 967. Numbers With Same Consecutive Differences                   | [Link](https://leetcode.com/problems/numbers-with-same-consecutive-differences/)                   | [Link](./lib/medium/967_numbers_with_same_consecutive_differences.rb)                   | [Link](./test/medium/test_967_numbers_with_same_consecutive_differences.rb)                   |
 | 973. K Closest Points to Origin                                  | [Link](https://leetcode.com/problems/k-closest-points-to-origin/)                                  | [Link](./lib/medium/973_k_closest_points_to_origin.rb)                                  | [Link](./test/medium/test_973_k_closest_points_to_origin.rb)                                  |
+| 979. Distribute Coins in Binary Tree                             | [Link](https://leetcode.com/problems/distribute-coins-in-binary-tree/)                             | [Link](./lib/medium/979_distribute_coins_in_binary_tree.rb)                             | [Link](./test/medium/test_979_distribute_coins_in_binary_tree.rb)                             |
 | 1400. Construct K Palindrome Strings                             | [Link](https://leetcode.com/problems/construct-k-palindrome-strings/)                              | [Link](./lib/medium/1400_construct_k_palindrome_strings.rb)                             | [Link](./test/medium/test_1400_construct_k_palindrome_strings.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)                                |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 26246322..8eb3eb62 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 = '8.1.4'
+  s.version = '8.1.5'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/979_distribute_coins_in_binary_tree.rb b/lib/medium/979_distribute_coins_in_binary_tree.rb
new file mode 100644
index 00000000..e941b731
--- /dev/null
+++ b/lib/medium/979_distribute_coins_in_binary_tree.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/distribute-coins-in-binary-tree/
+# @param {TreeNode} root
+# @return {Integer}
+def distribute_coins(root)
+  @result = 0
+  dfs_for_distribute_coins(root)
+
+  @result
+end
+
+private
+
+# @param {TreeNode} node
+# @return {Integer}
+def dfs_for_distribute_coins(node)
+  return 0 unless node
+
+  left = dfs_for_distribute_coins(node.left)
+  right = dfs_for_distribute_coins(node.right)
+
+  @result += left.abs + right.abs
+
+  node.val + left + right - 1
+end
diff --git a/test/medium/test_979_distribute_coins_in_binary_tree.rb b/test/medium/test_979_distribute_coins_in_binary_tree.rb
new file mode 100644
index 00000000..c78d3ebc
--- /dev/null
+++ b/test/medium/test_979_distribute_coins_in_binary_tree.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/979_distribute_coins_in_binary_tree'
+require 'minitest/autorun'
+
+class DistributeCoinsToBinaryTreeTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      2,
+      distribute_coins(
+        ::TreeNode.new(
+          3,
+          ::TreeNode.new(0),
+          ::TreeNode.new(0)
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      3,
+      distribute_coins(
+        ::TreeNode.new(
+          0,
+          ::TreeNode.new(3),
+          ::TreeNode.new(0)
+        )
+      )
+    )
+  end
+end