2025-01-09 v. 7.8.5: added "363. Max Sum of Rectangle No Larger Than K"

Author: fartem

README.md

@@ -654,3 +654,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 239. Sliding Window Maximum                   | [Link](https://leetcode.com/problems/sliding-window-maximum/)                    | [Link](./lib/hard/239_sliding_window_maximum.rb)                   | [Link](./test/hard/test_239_sliding_window_maximum.rb)                   |
 | 297. Serialize and Deserialize Binary Tree    | [Link](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)     | [Link](./lib/hard/297_serialize_and_deserialize_binary_tree.rb)    | [Link](./test/hard/test_297_serialize_and_deserialize_binary_tree.rb)    |
 | 336. Palindrome Pairs                         | [Link](https://leetcode.com/problems/palindrome-pairs/)                          | [Link](./lib/hard/336_palindrome_pairs.rb)                         | [Link](./test/hard/test_336_palindrome_pairs.rb)                         |
+| 363. Max Sum of Rectangle No Larger Than K    | [Link](https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k/)     | [Link](./lib/hard/363_max_sum_of_rectangle_no_larger_than_k.rb)    | [Link](./test/hard/test_363_max_sum_of_rectangle_no_larger_than_k.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 = '7.8.4'
+  s.version = '7.8.5'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/hard/363_max_sum_of_rectangle_no_larger_than_k.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/max-sum-of-rectangle-no-larger-than-k/
+# @param {Integer[][]} matrix
+# @param {Integer} k
+# @return {Integer}
+def max_sum_submatrix(matrix, k)
+  m = matrix.length
+  n = matrix[0].length
+
+  result = -::Float::INFINITY
+
+  (0...n).each do |start_col|
+    sum_row = ::Array.new(m, 0)
+
+    (start_col...n).each do |last_col|
+      sum = 0
+
+      accum_sums = [0]
+      (0...m).each do |last_row|
+        sum += (sum_row[last_row] += matrix[last_row][last_col])
+
+        excess = accum_sums.bsearch { |x| x >= sum - k }
+
+        result = [result, sum - excess].max unless excess.nil?
+
+        idx = accum_sums.bsearch_index { |x| x >= sum }
+
+        accum_sums.insert(idx || (last_row + 1), sum)
+      end
+    end
+  end
+
+  result
+end

test/hard/test_363_max_sum_of_rectangle_no_larger_than_k.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/hard/363_max_sum_of_rectangle_no_larger_than_k'
+require 'minitest/autorun'
+
+class MaxSumOfRectangleNoLargerThanKTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      2,
+      max_sum_submatrix(
+        [
+          [1, 0, 1],
+          [0, -2, 3]
+        ],
+        2
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      3,
+      max_sum_submatrix(
+        [
+          [2, 2, -1]
+        ],
+        3
+      )
+    )
+  end
+end