From 75d367b11287ae4f17265b1bcd897b13e6672d5b Mon Sep 17 00:00:00 2001 From: fartem Date: Thu, 13 Feb 2025 07:52:01 +0300 Subject: [PATCH] 2025-02-13 v. 8.5.4: added "1382. Balance a Binary Search Tree" --- README.md | 1 + leetcode-ruby.gemspec | 2 +- .../1382_balance_a_binary_search_tree.rb | 41 +++++++++++++++++++ .../test_1382_balance_a_binary_search_tree.rb | 38 +++++++++++++++++ 4 files changed, 81 insertions(+), 1 deletion(-) create mode 100644 lib/medium/1382_balance_a_binary_search_tree.rb create mode 100644 test/medium/test_1382_balance_a_binary_search_tree.rb diff --git a/README.md b/README.md index 10aeb7b0..29d3c68b 100644 --- a/README.md +++ b/README.md @@ -687,6 +687,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/). | 1367. Linked List in Binary Tree | [Link](https://leetcode.com/problems/linked-list-in-binary-tree/) | [Link](./lib/medium/1367_linked_list_in_binary_tree.rb) | [Link](./test/medium/test_1367_linked_list_in_binary_tree.rb) | | 1376. Time Needed to Inform All Employees | [Link](https://leetcode.com/problems/time-needed-to-inform-all-employees/) | [Link](./lib/medium/1376_time_needed_to_inform_all_employees.rb) | [Link](./test/medium/test_1376_time_needed_to_inform_all_employees.rb) | | 1381. Design a Stack With Increment Operation | [Link](https://leetcode.com/problems/design-a-stack-with-increment-operation/) | [Link](./lib/medium/1381_design_a_stack_with_increment_operation.rb) | [Link](./test/medium/test_1381_design_a_stack_with_increment_operation.rb) | +| 1382. Balance a Binary Search Tree | [Link](https://leetcode.com/problems/balance-a-binary-search-tree/) | [Link](./lib/medium/1382_balance_a_binary_search_tree.rb) | [Link](./test/medium/test_1382_balance_a_binary_search_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 9afc382b..43860d89 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 = '8.5.4' + s.version = '8.5.5' s.license = 'MIT' s.files = ::Dir['lib/**/*.rb'] + %w[README.md] s.executable = 'leetcode-ruby' diff --git a/lib/medium/1382_balance_a_binary_search_tree.rb b/lib/medium/1382_balance_a_binary_search_tree.rb new file mode 100644 index 00000000..1d0b0805 --- /dev/null +++ b/lib/medium/1382_balance_a_binary_search_tree.rb @@ -0,0 +1,41 @@ +# frozen_string_literal: true + +require_relative '../common/binary_tree' + +# https://leetcode.com/problems/balance-a-binary-search-tree/ +# @param {TreeNode} root +# @return {TreeNode} +def balance_bst(root) + nums = [] + dfs_for_balance_bst(root, nums) + + build_for_balance_bst(nums, 0, nums.size - 1) +end + +private + +# @param {TreeNode} node +# @param {Integer} nums +# @return {Void} +def dfs_for_balance_bst(node, nums) + return unless node + + dfs_for_balance_bst(node.left, nums) + nums << node.val + dfs_for_balance_bst(node.right, nums) +end + +# @param {Integer[]} nums +# @param {Integer} left +# @param {Integer} right +# @return {TreeNode} +def build_for_balance_bst(nums, left, right) + return if left > right + + middle = left + (right - left) / 2 + node = ::TreeNode.new(nums[middle]) + node.left = build_for_balance_bst(nums, left, middle - 1) + node.right = build_for_balance_bst(nums, middle + 1, right) + + node +end diff --git a/test/medium/test_1382_balance_a_binary_search_tree.rb b/test/medium/test_1382_balance_a_binary_search_tree.rb new file mode 100644 index 00000000..78f10b4a --- /dev/null +++ b/test/medium/test_1382_balance_a_binary_search_tree.rb @@ -0,0 +1,38 @@ +# frozen_string_literal: true + +require_relative '../test_helper' +require_relative '../../lib/common/binary_tree' +require_relative '../../lib/medium/1382_balance_a_binary_search_tree' +require 'minitest/autorun' + +class BalanceABinarySearchTreeTest < ::Minitest::Test + def test_default_one + assert( + ::TreeNode.are_equals( + ::TreeNode.build_tree( + [2, 1, 3, nil, nil, nil, 4] + ), + balance_bst( + ::TreeNode.build_tree( + [1, nil, 2, nil, 3, nil, 4, nil, nil] + ) + ) + ) + ) + end + + def test_default_two + assert( + ::TreeNode.are_equals( + ::TreeNode.build_tree( + [2, 1, 3] + ), + balance_bst( + ::TreeNode.build_tree( + [2, 1, 3] + ) + ) + ) + ) + end +end