From 39e3cb01e24828e3b72930c08f9a27a604d0a133 Mon Sep 17 00:00:00 2001
From: fartem <jaman.smlnsk@gmail.com>
Date: Fri, 13 Dec 2024 10:24:10 +0300
Subject: [PATCH] 2024-12-13 v. 7.3.2: added "621. Task Scheduler"

---
 README.md                              |  1 +
 leetcode-ruby.gemspec                  |  2 +-
 lib/medium/621_task_scheduler.rb       | 26 ++++++++++++++++++
 test/medium/test_621_task_scheduler.rb | 37 ++++++++++++++++++++++++++
 4 files changed, 65 insertions(+), 1 deletion(-)
 create mode 100644 lib/medium/621_task_scheduler.rb
 create mode 100644 test/medium/test_621_task_scheduler.rb

diff --git a/README.md b/README.md
index 5e1d0488..342a3d54 100644
--- a/README.md
+++ b/README.md
@@ -596,3 +596,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 581. Shortest Unsorted Continuous Subarray                      | [Link](https://leetcode.com/problems/shortest-unsorted-continuous-subarray/)                      | [Link](./lib/medium/581_shortest_unsorted_continuous_subarray.rb)                      | [Link](./test/medium/test_581_shortest_unsorted_continuous_subarray.rb)                      |
 | 606. Construct String from Binary Tree                          | [Link](https://leetcode.com/problems/construct-string-from-binary-tree/)                          | [Link](./lib/medium/606_construct_string_from_binary_tree.rb)                          | [Link](./test/medium/test_606_construct_string_from_binary_tree.rb)                          |
 | 609. Find Duplicate File in System                              | [Link](https://leetcode.com/problems/find-duplicate-file-in-system/)                              | [Link](./lib/medium/609_find_duplicate_file_in_system.rb)                              | [Link](./test/medium/test_609_find_duplicate_file_in_system.rb)                              |
+| 621. Task Scheduler                                             | [Link](https://leetcode.com/problems/task-scheduler/)                                             | [Link](./lib/medium/621_task_scheduler.rb)                                             | [Link](./test/medium/test_621_task_scheduler.rb)                                             |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index e9807e63..18184910 100644
--- a/leetcode-ruby.gemspec
+++ b/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 = '7.3.1'
+  s.version = '7.3.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/621_task_scheduler.rb b/lib/medium/621_task_scheduler.rb
new file mode 100644
index 00000000..8f5d0d91
--- /dev/null
+++ b/lib/medium/621_task_scheduler.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/task-scheduler/
+# @param {Character[]} tasks
+# @param {Integer} n
+# @return {Integer}
+def least_interval(tasks, n)
+  count = ::Array.new(128, 0)
+  max = 0
+  max_count = 0
+
+  tasks.each do |task|
+    i = task.ord
+    count[i] += 1
+    c = count[i]
+
+    if c == max
+      max_count += 1
+    elsif c > max
+      max = c
+      max_count = 1
+    end
+  end
+
+  [tasks.size, (max - 1) * (n + 1) + max_count].max
+end
diff --git a/test/medium/test_621_task_scheduler.rb b/test/medium/test_621_task_scheduler.rb
new file mode 100644
index 00000000..1f76be30
--- /dev/null
+++ b/test/medium/test_621_task_scheduler.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/621_task_scheduler'
+require 'minitest/autorun'
+
+class TaskSchedulerTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      8,
+      least_interval(
+        %w[A A A B B B],
+        2
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      6,
+      least_interval(
+        %w[A C A B D B],
+        1
+      )
+    )
+  end
+
+  def test_default_three
+    assert_equal(
+      10,
+      least_interval(
+        %w[A A A B B B],
+        3
+      )
+    )
+  end
+end