2025-01-01 v. 7.5.8: added "814. Binary Tree Pruning"

Author: fartem

README.md

@@ -622,3 +622,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 763. Partition Labels                                           | [Link](https://leetcode.com/problems/partition-labels/)                                           | [Link](./lib/medium/763_partition_labels.rb)                                           | [Link](./test/medium/test_763_partition_labels.rb)                                           |
 | 784. Letter Case Permutation                                    | [Link](https://leetcode.com/problems/letter-case-permutation/)                                    | [Link](./lib/medium/784_letter_case_permutation.rb)                                    | [Link](./test/medium/test_784_letter_case_permutation.rb)                                    |
 | 797. All Paths From Source to Target                            | [Link](https://leetcode.com/problems/all-paths-from-source-to-target/)                            | [Link](./lib/medium/797_all_paths_from_source_to_target.rb)                            | [Link](./test/medium/test_797_all_paths_from_source_to_target.rb)                            |
+| 814. Binary Tree Pruning                                        | [Link](https://leetcode.com/problems/binary-tree-pruning/)                                        | [Link](./lib/medium/814_binary_tree_pruning.rb)                                        | [Link](./test/medium/test_814_binary_tree_pruning.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 = '7.5.7.1'
+  s.version = '7.5.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/814_binary_tree_pruning.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/binary-tree-pruning/
+# @param {TreeNode} root
+# @return {TreeNode}
+def prune_tree(root) = has_one_in_prune_tree?(root) ? root : nil
+
+private
+
+# @param {TreeNode} node
+# @return {Boolean}
+def has_one_in_prune_tree?(node)
+  return false unless node
+
+  has_one_at_left = has_one_in_prune_tree?(node.left)
+  has_one_at_right = has_one_in_prune_tree?(node.right)
+
+  node.left = nil unless has_one_at_left
+  node.right = nil unless has_one_at_right
+
+  node.val == 1 || has_one_at_left || has_one_at_right
+end

test/medium/test_814_binary_tree_pruning.rb

@@ -0,0 +1,111 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/814_binary_tree_pruning'
+require 'minitest/autorun'
+
+class BinaryTreePruningTest < ::Minitest::Test
+  def test_default_one
+    assert(
+      ::TreeNode.are_equals(
+        ::TreeNode.new(
+          1,
+          nil,
+          ::TreeNode.new(
+            0,
+            nil,
+            ::TreeNode.new(1)
+          )
+        ),
+        prune_tree(
+          ::TreeNode.new(
+            1,
+            nil,
+            ::TreeNode.new(
+              0,
+              ::TreeNode.new(0),
+              ::TreeNode.new(1)
+            )
+          )
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert(
+      ::TreeNode.are_equals(
+        ::TreeNode.new(
+          1,
+          nil,
+          ::TreeNode.new(
+            1,
+            nil,
+            ::TreeNode.new(1)
+          )
+        ),
+        prune_tree(
+          ::TreeNode.new(
+            1,
+            ::TreeNode.new(
+              0,
+              ::TreeNode.new(0),
+              ::TreeNode.new(0)
+            ),
+            ::TreeNode.new(
+              1,
+              ::TreeNode.new(0),
+              ::TreeNode.new(1)
+            )
+          )
+        )
+      )
+    )
+  end
+
+  def test_default_three
+    assert(
+      ::TreeNode.are_equals(
+        ::TreeNode.new(
+          1,
+          ::TreeNode.new(
+            1,
+            ::TreeNode.new(
+              1,
+              ::TreeNode.new(1),
+              ::TreeNode.new(1)
+            )
+          ),
+          ::TreeNode.new(
+            0,
+            nil,
+            ::TreeNode.new(1)
+          )
+        ),
+        prune_tree(
+          ::TreeNode.new(
+            1,
+            ::TreeNode.new(
+              1,
+              ::TreeNode.new(
+                1,
+                ::TreeNode.new(
+                  1,
+                  ::TreeNode.new(0),
+                  nil
+                ),
+                ::TreeNode.new(1)
+              )
+            ),
+            ::TreeNode.new(
+              0,
+              ::TreeNode.new(0),
+              ::TreeNode.new(1)
+            )
+          )
+        )
+      )
+    )
+  end
+end