Merge pull request #781 from fartem/449_Serialize_and_Deserialize_BST

2024-11-25 v. 7.1.0: added "449. Serialize and Deserialize BST"

Author: fartem

README.md

@@ -575,3 +575,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 442. Find All Duplicates in an Array                            | [Link](https://leetcode.com/problems/find-all-duplicates-in-an-array/)                            | [Link](./lib/medium/442_find_all_duplicates_in_an_array.rb)                            | [Link](./test/medium/test_442_find_all_duplicates_in_an_array.rb)                            |
 | 443. String Compression                                         | [Link](https://leetcode.com/problems/string-compression/)                                         | [Link](./lib/medium/443_string_compression.rb)                                         | [Link](./test/medium/test_443_string_compression.rb)                                         |
 | 445. Add Two Numbers II                                         | [Link](https://leetcode.com/problems/add-two-numbers-ii/)                                         | [Link](./lib/medium/445_add_two_numbers_ii.rb)                                         | [Link](./test/medium/test_445_add_two_numbers_ii.rb)                                         |
+| 449. Serialize and Deserialize BST                              | [Link](https://leetcode.com/problems/serialize-and-deserialize-bst/)                              | [Link](./lib/medium/449_serialize_and_deserialize_bst.rb)                              | [Link](./test/medium/test_449_serialize_and_deserialize_bst.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 = '7.0.9.1'
+  s.version = '7.1.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/449_serialize_and_deserialize_bst.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/serialize-and-deserialize-bst/
+# @param {TreeNode} root
+# @return {String}
+def serialize(root)
+  return '#' unless root
+
+  result = []
+  result << root.val
+
+  left = serialize(root.left)
+  result << ','
+  result << left
+
+  right = serialize(root.right)
+  result << ','
+  result << right
+
+  result.join
+end
+
+# @param {String} data
+# @return {TreeNode}
+def deserialize(data)
+  raw_data = data.split(',')
+
+  deserialize_from_string(raw_data, 0, raw_data.size - 1)
+end
+
+# @param {String[]} data
+# @param {Integer} l
+# @param {Integer} r
+# @return {TreeNode}
+def deserialize_from_string(data, l, r)
+  return if data[l] == '#'
+
+  root = ::TreeNode.new(data[l].to_i)
+  built = false
+
+  ((l + 1)..r).each do |i|
+    value = data[i]
+
+    next if value == '#'
+
+    next unless value.to_i > root.val
+
+    built = true
+    root.left = deserialize_from_string(data, l + 1, i - 1)
+    root.right = deserialize_from_string(data, i, r)
+
+    break
+  end
+
+  root.left = deserialize_from_string(data, l + 1, r) unless built
+
+  root
+end

test/medium/test_449_serialize_and_deserialize_bst.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/449_serialize_and_deserialize_bst'
+require 'minitest/autorun'
+
+class SerializeAndDeserializeBSTTest < ::Minitest::Test
+  def test_default_one
+    node = ::TreeNode.new(
+      2,
+      ::TreeNode.new(1),
+      ::TreeNode.new(3)
+    )
+    result = serialize(node)
+
+    assert(
+      ::TreeNode.are_equals(
+        deserialize(result),
+        ::TreeNode.new(
+          2,
+          ::TreeNode.new(1),
+          ::TreeNode.new(3)
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    node = ::TreeNode.new
+    result = serialize(node)
+
+    assert(
+      ::TreeNode.are_equals(
+        deserialize(result),
+        ::TreeNode.new
+      )
+    )
+  end
+end