2025-01-18 v. 8.1.6: added "1368. Minimum Cost to Make at Least One Valid Path in a Grid"

Author: fartem

README.md

@@ -683,5 +683,6 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 968. Binary Tree Cameras                                      | [Link](https://leetcode.com/problems/binary-tree-cameras/)                                     | [Link](./lib/hard/968_binary_tree_cameras.rb)                                      | [Link](./test/hard/test_968_binary_tree_cameras.rb)                                      |
 | 1106. Parsing A Boolean Expression                            | [Link](https://leetcode.com/problems/parsing-a-boolean-expression/)                            | [Link](./lib/hard/1106_parsing_a_boolean_expression.rb)                            | [Link](./test/hard/test_1106_parsing_a_boolean_expression.rb)                            |
 | 1220. Count Vowels Permutation                                | [Link](https://leetcode.com/problems/count-vowels-permutation/)                                | [Link](./lib/hard/1220_count_vowels_permutation.rb)                                | [Link](./test/hard/test_1220_count_vowels_permutation.rb)                                |
+| 1368. Minimum Cost to Make at Least One Valid Path in a Grid  | [Link](https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/)  | [Link](./lib/hard/1368_minimum_cost_to_make_at_least_one_valid_path_in_a_grid.rb)  | [Link](./test/hard/test_1368_minimum_cost_to_make_at_least_one_valid_path_in_a_grid.rb)  |
 | 1770. Maximum Score from Performing Multiplication Operations | [Link](https://leetcode.com/problems/maximum-score-from-performing-multiplication-operations/) | [Link](./lib/hard/1770_maximum_score_from_performing_multiplication_operations.rb) | [Link](./test/hard/test_1770_maximum_score_from_performing_multiplication_operations.rb) |
 | 1944. Number of Visible People in a Queue                     | [Link](https://leetcode.com/problems/number-of-visible-people-in-a-queue/)                     | [Link](./lib/hard/1944_number_of_visible_people_in_a_queue.rb)                     | [Link](./test/hard/test_1944_number_of_visible_people_in_a_queue.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 = '8.1.5'
+  s.version = '8.1.6'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/hard/1368_minimum_cost_to_make_at_least_one_valid_path_in_a_grid.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: false
+
+# https://leetcode.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid/
+# @param {Integer[][]} grid
+# @return {Integer}
+def min_cost(grid)
+  m = grid.length
+  n = grid[0].length
+  dist = ::Array.new(m) { ::Array.new(n, ::Float::INFINITY) }
+  dist[0][0] = 0
+
+  dirs = [
+    [0, 1],
+    [0, -1],
+    [1, 0],
+    [-1, 0]
+  ]
+  pq = [[0, 0, 0]]
+
+  until pq.empty?
+    cost, row, col = pq.shift
+
+    next if cost > dist[row][col]
+
+    4.times do |i|
+      new_row = row + dirs[i][0]
+      new_col = col + dirs[i][1]
+
+      next if new_row.negative? || new_row >= m || new_col.negative? || new_col >= n
+
+      new_cost = cost
+      new_cost += 1 if grid[row][col] != i + 1
+
+      next unless new_cost < dist[new_row][new_col]
+
+      dist[new_row][new_col] = new_cost
+      idx = pq.bsearch_index { |x| x[0] > new_cost } || pq.length
+      pq.insert(idx, [new_cost, new_row, new_col])
+    end
+  end
+
+  dist[m - 1][n - 1]
+end

test/hard/test_1368_minimum_cost_to_make_at_least_one_valid_path_in_a_grid.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: false
+
+require_relative '../test_helper'
+require_relative '../../lib/hard/1368_minimum_cost_to_make_at_least_one_valid_path_in_a_grid'
+require 'minitest/autorun'
+
+class MinimumCostToMakeAtLeastOneValidPathInAGridTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      3,
+      min_cost(
+        [
+          [1, 1, 1, 1],
+          [2, 2, 2, 2],
+          [1, 1, 1, 1],
+          [2, 2, 2, 2]
+        ]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      0,
+      min_cost(
+        [
+          [1, 1, 3],
+          [3, 2, 2],
+          [1, 1, 4]
+        ]
+      )
+    )
+  end
+
+  def test_default_three
+    assert_equal(
+      1,
+      min_cost(
+        [
+          [1, 2],
+          [4, 3]
+        ]
+      )
+    )
+  end
+end