Merge pull request #792 from fartem/515_Find_Largest_Value_in_Each_Tree_Row

2024-12-04 v. 7.2.1: added "515. Find Largest Value in Each Tree Row"

Author: fartem

README.md

@@ -586,3 +586,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 503. Next Greater Element II                                    | [Link](https://leetcode.com/problems/next-greater-element-ii/)                                    | [Link](./lib/medium/503_next_greater_element_ii.rb)                                    | [Link](./test/medium/test_503_next_greater_element_ii.rb)                                    |
 | 508. Most Frequent Subtree Sum                                  | [Link](https://leetcode.com/problems/most-frequent-subtree-sum/)                                  | [Link](./lib/medium/508_most_frequent_subtree_sum.rb)                                  | [Link](./test/medium/test_508_most_frequent_subtree_sum.rb)                                  |
 | 513. Find Bottom Left Tree Value                                | [Link](https://leetcode.com/problems/find-bottom-left-tree-value/)                                | [Link](./lib/medium/513_find_bottom_left_tree_value.rb)                                | [Link](./test/medium/test_513_find_bottom_left_tree_value.rb)                                |
+| 515. Find Largest Value in Each Tree Row                        | [Link](https://leetcode.com/problems/find-largest-value-in-each-tree-row/)                        | [Link](./lib/medium/515_find_largest_value_in_each_tree_row.rb)                        | [Link](./test/medium/test_515_find_largest_value_in_each_tree_row.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 = '7.2.0'
+  s.version = '7.2.1'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/515_find_largest_value_in_each_tree_row.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/find-largest-value-in-each-tree-row/
+# @param {TreeNode} root
+# @return {Integer[]}
+def largest_values(root)
+  return [] unless root
+
+  result = []
+  nodes = [root]
+  until nodes.empty?
+    size = nodes.size
+    max = -::Float::INFINITY
+    (0...size).each do |_|
+      node = nodes.delete_at(0)
+
+      max = node.val if node.val > max
+
+      nodes << node.left if node.left
+      nodes << node.right if node.right
+    end
+
+    result << max
+  end
+
+  result
+end

test/medium/test_515_find_largest_value_in_each_tree_row.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/515_find_largest_value_in_each_tree_row'
+require 'minitest/autorun'
+
+class FindLargestValueInEachTreeRowTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      [1, 3, 9],
+      largest_values(
+        ::TreeNode.new(
+          1,
+          ::TreeNode.new(
+            3,
+            ::TreeNode.new(5),
+            ::TreeNode.new(3)
+          ),
+          ::TreeNode.new(
+            2,
+            nil,
+            ::TreeNode.new(9)
+          )
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      [1, 3],
+      largest_values(
+        ::TreeNode.new(
+          1,
+          ::TreeNode.new(2),
+          ::TreeNode.new(3)
+        )
+      )
+    )
+  end
+end