2025-01-24 v. 8.2.7: added "1038. Binary Search Tree to Greater Sum Tree"

Author: fartem

README.md

@@ -659,6 +659,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 1023. Camelcase Matching                                         | [Link](https://leetcode.com/problems/camelcase-matching/)                                          | [Link](./lib/medium/1023_camelcase_matching.rb)                                         | [Link](./test/medium/test_1023_camelcase_matching.rb)                                         |
 | 1026. Maximum Difference Between Node and Ancestor               | [Link](https://leetcode.com/problems/maximum-difference-between-node-and-ancestor/)                | [Link](./lib/medium/1026_maximum_difference_between_node_and_ancestor.rb)               | [Link](./test/medium/test_1026_maximum_difference_between_node_and_ancestor.rb)               |
 | 1038. Binary Search Tree to Greater Sum Tree                     | [Link](https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree/)                      | [Link](./lib/medium/1038_binary_search_tree_to_greater_sum_tree.rb)                     | [Link](./test/medium/test_1038_binary_search_tree_to_greater_sum_tree.rb)                     |
+| 1043. Partition Array for Maximum Sum                            | [Link](https://leetcode.com/problems/partition-array-for-maximum-sum/)                             | [Link](./lib/medium/1043_partition_array_for_maximum_sum.rb)                            | [Link](./test/medium/test_1043_partition_array_for_maximum_sum.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)                                |

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 = '8.2.6.1'
+  s.version = '8.2.7'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/1038_binary_search_tree_to_greater_sum_tree.rb

@@ -1,23 +1,26 @@
 # frozen_string_literal: true
 
 # https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree/
-# @param {Integer[]} arr
-# @param {Integer} k
-# @return {Integer}
-def max_sum_after_partitioning(arr, k)
-  partitioned = ::Array.new(arr.size + 1, 0)
+# @param {TreeNode} root
+# @return {TreeNode}
+def bst_to_gst(root)
+  @sum = 0
+  transform_tree(root)
 
-  (1..arr.size).each do |i|
-    max = 0
-    val = 0
+  root
+end
+
+private
+
+# @param {TreeNode} node
+# @return {Void}
+def transform_tree(node)
+  return unless node
 
-    [i, k].min.times do |j|
-      max = [max, arr[i - j - 1]].max
-      val = [partitioned[i - j - 1] + max * (j + 1), val].max
-    end
+  transform_tree(node.right)
 
-    partitioned[i] = val
-  end
+  @sum += node.val
+  node.val = @sum
 
-  partitioned[arr.size]
+  transform_tree(node.left)
 end

lib/medium/1043_partition_array_for_maximum_sum.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree/
+# @param {Integer[]} arr
+# @param {Integer} k
+# @return {Integer}
+def max_sum_after_partitioning(arr, k)
+  partitioned = ::Array.new(arr.size + 1, 0)
+
+  (1..arr.size).each do |i|
+    max = 0
+    val = 0
+
+    [i, k].min.times do |j|
+      max = [max, arr[i - j - 1]].max
+      val = [partitioned[i - j - 1] + max * (j + 1), val].max
+    end
+
+    partitioned[i] = val
+  end
+
+  partitioned[arr.size]
+end

test/medium/test_1038_binary_search_tree_to_greater_sum_tree.rb

@@ -1,36 +1,37 @@
 # frozen_string_literal: true
 
 require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
 require_relative '../../lib/medium/1038_binary_search_tree_to_greater_sum_tree'
 require 'minitest/autorun'
 
 class BinarySearchTreeToGreaterSumTreeTest < ::Minitest::Test
   def test_default_one
-    assert_equal(
-      84,
-      max_sum_after_partitioning(
-        [1, 15, 7, 9, 2, 5, 10],
-        3
+    assert(
+      ::TreeNode.are_equals(
+        ::TreeNode.build_tree(
+          [30, 36, 21, 36, 35, 26, 15, nil, nil, nil, 33, nil, nil, nil, 8]
+        ),
+        bst_to_gst(
+          ::TreeNode.build_tree(
+            [4, 1, 6, 0, 2, 5, 7, nil, nil, nil, 3, nil, nil, nil, 8]
+          )
+        )
       )
     )
   end
 
   def test_default_two
-    assert_equal(
-      83,
-      max_sum_after_partitioning(
-        [1, 4, 1, 5, 7, 3, 6, 1, 9, 9, 3],
-        4
-      )
-    )
-  end
-
-  def test_default_three
-    assert_equal(
-      1,
-      max_sum_after_partitioning(
-        [1],
-        1
+    assert(
+      ::TreeNode.are_equals(
+        ::TreeNode.build_tree(
+          [1, nil, 1]
+        ),
+        bst_to_gst(
+          ::TreeNode.build_tree(
+            [0, nil, 1]
+          )
+        )
       )
     )
   end

test/medium/test_1043_partition_array_for_maximum_sum.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/1043_partition_array_for_maximum_sum'
+require 'minitest/autorun'
+
+class PartitionArrayForMaximumSumTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      84,
+      max_sum_after_partitioning(
+        [1, 15, 7, 9, 2, 5, 10],
+        3
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      83,
+      max_sum_after_partitioning(
+        [1, 4, 1, 5, 7, 3, 6, 1, 9, 9, 3],
+        4
+      )
+    )
+  end
+
+  def test_default_three
+    assert_equal(
+      1,
+      max_sum_after_partitioning(
+        [1],
+        1
+      )
+    )
+  end
+end