From caae103f255256d181ab48e08b67da048e7b58ad Mon Sep 17 00:00:00 2001 From: fartem Date: Wed, 22 Jan 2025 11:37:53 +0300 Subject: [PATCH] 2025-01-22 v. 8.2.2: added "1008. Construct Binary Search Tree from Preorder Traversal" --- README.md | 1 + leetcode-ruby.gemspec | 2 +- ...ary_search_tree_from_preorder_traversal.rb | 34 ++++++++++++++ .../988_smallest_string_starting_from_leaf.rb | 2 +- ...ary_search_tree_from_preorder_traversal.rb | 46 +++++++++++++++++++ 5 files changed, 83 insertions(+), 2 deletions(-) create mode 100644 lib/medium/1008_construct_binary_search_tree_from_preorder_traversal.rb create mode 100644 test/medium/test_1008_construct_binary_search_tree_from_preorder_traversal.rb diff --git a/README.md b/README.md index 5f17585d..18650b9c 100644 --- a/README.md +++ b/README.md @@ -654,6 +654,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/). | 985. Sum of Even Numbers After Queries | [Link](https://leetcode.com/problems/sum-of-even-numbers-after-queries/) | [Link](./lib/medium/985_sum_of_even_numbers_after_queries.rb) | [Link](./test/medium/test_985_sum_of_even_numbers_after_queries.rb) | | 988. Smallest String Starting From Leaf | [Link](https://leetcode.com/problems/smallest-string-starting-from-leaf/) | [Link](./lib/medium/988_smallest_string_starting_from_leaf.rb) | [Link](./test/medium/test_988_smallest_string_starting_from_leaf.rb) | | 998. Maximum Binary Tree II | [Link](https://leetcode.com/problems/maximum-binary-tree-ii/) | [Link](./lib/medium/998_maximum_binary_tree_ii.rb) | [Link](./test/medium/test_998_maximum_binary_tree_ii.rb) | +| 1008. Construct Binary Search Tree from Preorder Traversal | [Link](https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/) | [Link](./lib/medium/1008_construct_binary_search_tree_from_preorder_traversal.rb) | [Link](./test/medium/test_1008_construct_binary_search_tree_from_preorder_traversal.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 befe9e38..ff5e878a 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 = '8.2.1' + s.version = '8.2.2' s.license = 'MIT' s.files = ::Dir['lib/**/*.rb'] + %w[README.md] s.executable = 'leetcode-ruby' diff --git a/lib/medium/1008_construct_binary_search_tree_from_preorder_traversal.rb b/lib/medium/1008_construct_binary_search_tree_from_preorder_traversal.rb new file mode 100644 index 00000000..d61b1040 --- /dev/null +++ b/lib/medium/1008_construct_binary_search_tree_from_preorder_traversal.rb @@ -0,0 +1,34 @@ +# frozen_string_literal: true + +require_relative '../common/binary_tree' + +# https://leetcode.com/problems/construct-binary-search-tree-from-preorder-traversal/ +# @param {Integer[]} preorder +# @return {TreeNode} +def bst_from_preorder(preorder) + construct_bst_from_preorder(preorder, 0, preorder.size - 1) +end + +private + +# @param {Integer[]} preorder +# @param {Integer} start +# @param {Integer} nd +# @return {TreeNode} +def construct_bst_from_preorder(preorder, start, nd) + return if start > nd + + node = ::TreeNode.new(preorder[start]) + + index = start + while index <= nd + break if preorder[index] > node.val + + index += 1 + end + + node.left = construct_bst_from_preorder(preorder, start + 1, index - 1) + node.right = construct_bst_from_preorder(preorder, index, nd) + + node +end diff --git a/lib/medium/988_smallest_string_starting_from_leaf.rb b/lib/medium/988_smallest_string_starting_from_leaf.rb index 96ff7551..0d60e1cb 100644 --- a/lib/medium/988_smallest_string_starting_from_leaf.rb +++ b/lib/medium/988_smallest_string_starting_from_leaf.rb @@ -13,7 +13,7 @@ def smallest_from_leaf(root) private # @param {TreeNode} root -# @param {Array} curr +# @param {String} curr # @return {Void} def find_smallest_string_staring_from_leaf(root, curr) return unless root diff --git a/test/medium/test_1008_construct_binary_search_tree_from_preorder_traversal.rb b/test/medium/test_1008_construct_binary_search_tree_from_preorder_traversal.rb new file mode 100644 index 00000000..64d27e24 --- /dev/null +++ b/test/medium/test_1008_construct_binary_search_tree_from_preorder_traversal.rb @@ -0,0 +1,46 @@ +# frozen_string_literal: true + +require_relative '../test_helper' +require_relative '../../lib/common/binary_tree' +require_relative '../../lib/medium/1008_construct_binary_search_tree_from_preorder_traversal' +require 'minitest/autorun' + +class ConstructBinarySearchTreeFromPreorderTraversalTest < ::Minitest::Test + def test_default_one + assert( + ::TreeNode.are_equals( + ::TreeNode.new( + 8, + ::TreeNode.new( + 5, + ::TreeNode.new(1), + ::TreeNode.new(7) + ), + ::TreeNode.new( + 10, + nil, + ::TreeNode.new(12) + ) + ), + bst_from_preorder( + [8, 5, 1, 7, 10, 12] + ) + ) + ) + end + + def test_default_two + assert( + ::TreeNode.are_equals( + ::TreeNode.new( + 1, + nil, + ::TreeNode.new(3) + ), + bst_from_preorder( + [1, 3] + ) + ) + ) + end +end