Merge pull request #791 from fartem/513_Find_Bottom_Left_Tree_Value

2024-12-04 v. 7.2.0: added "513. Find Bottom Left Tree Value"

Author: fartem

README.md

@@ -585,3 +585,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 474. Ones and Zeroes                                            | [Link](https://leetcode.com/problems/ones-and-zeroes/)                                            | [Link](./lib/medium/474_ones_and_zeroes.rb)                                            | [Link](./test/medium/test_474_ones_and_zeroes.rb)                                            |
 | 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)                                |

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 = '7.1.9'
+  s.version = '7.2.0'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/513_find_bottom_left_tree_value.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+$path = -1
+$value = 0
+
+# https://leetcode.com/problems/find-bottom-left-tree-value/
+# @param {TreeNode} root
+# @return {Integer}
+def find_bottom_left_value(root)
+  $path = -1
+  $value = 0
+
+  apply_to_find_bottom_left_value(root, 0)
+
+  $value
+end
+
+private
+
+# @param {TreeNode} node
+# @param {Integer} curr
+# @return {Void}
+def apply_to_find_bottom_left_value(node, curr)
+  return unless node
+
+  if $path < curr
+    $path = curr
+    $value = node.val
+  end
+
+  apply_to_find_bottom_left_value(node.left, curr + 1)
+  apply_to_find_bottom_left_value(node.right, curr + 1)
+end

test/medium/test_513_find_bottom_left_tree_value.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/common/binary_tree'
+require_relative '../../lib/medium/513_find_bottom_left_tree_value'
+require 'minitest/autorun'
+
+class FindBottomLeftTreeValueTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      1,
+      find_bottom_left_value(
+        ::TreeNode.new(
+          2,
+          ::TreeNode.new(1),
+          ::TreeNode.new(3)
+        )
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      7,
+      find_bottom_left_value(
+        ::TreeNode.new(
+          1,
+          ::TreeNode.new(
+            2,
+            ::TreeNode.new(4),
+            nil
+          ),
+          ::TreeNode.new(
+            3,
+            ::TreeNode.new(
+              5,
+              ::TreeNode.new(7),
+              nil
+            ),
+            ::TreeNode.new(6)
+          )
+        )
+      )
+    )
+  end
+end