Merge pull request #739 from fartem/227_Basic_Calculator_II

2024-10-01 v. 6.7.2: added "227. Basic Calculator II"

Author: fartem

README.md

@@ -537,3 +537,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 208. Implement Trie (Prefix Tree)                               | [Link](https://leetcode.com/problems/implement-trie-prefix-tree/)                                 | [Link](./lib/medium/208_implement_trie_prefix_tree.rb)                                 | [Link](./test/medium/test_208_implement_trie_prefix_tree.rb)                                 |
 | 209. Minimum Size Subarray Sum                                  | [Link](https://leetcode.com/problems/minimum-size-subarray-sum/)                                  | [Link](./lib/medium/209_minimum_size_subarray_sum.rb)                                  | [Link](./test/medium/test_209_minimum_size_subarray_sum.rb)                                  |
 | 215. Kth Largest Element in an Array                            | [Link](https://leetcode.com/problems/kth-largest-element-in-an-array/)                            | [Link](./lib/medium/215_kth_largest_element_in_an_array.rb)                            | [Link](./test/medium/test_215_kth_largest_element_in_an_array.rb)                            |
+| 227. Basic Calculator II                                        | [Link](https://leetcode.com/problems/basic-calculator-ii/)                                        | [Link](./lib/medium/227_basic_calculator_ii.rb)                                        | [Link](./test/medium/test_227_basic_calculator_ii.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 = '6.7.1'
+  s.version = '6.7.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'

lib/medium/227_basic_calculator_ii.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/basic-calculator-ii/
+# @param {String} s
+# @return {Integer}
+def calculate(s)
+  stack = []
+  curr = 0
+  op = '+'
+
+  s.each_char do |c|
+    if c.match?(/[0-9]/)
+      curr = curr * 10 + c.to_i
+    elsif c != ' '
+      stack.push(
+        perform_operation(
+          stack,
+          op,
+          curr
+        )
+      )
+
+      curr = 0
+      op = c
+    end
+  end
+
+  stack.push(
+    perform_operation(
+      stack,
+      op,
+      curr
+    )
+  )
+
+  stack.sum
+end
+
+private
+
+# @param {Array} stack
+# @param {String} op
+# @param {Integer} num
+# @return {Integer}
+def perform_operation(stack, op, num)
+  case op
+  when '+'
+    num
+  when '-'
+    -num
+  when '*'
+    stack.pop * num
+  when '/'
+    (stack.pop.to_f / num).to_i
+  end
+end

test/medium/test_227_basic_calculator_ii.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/227_basic_calculator_ii'
+require 'minitest/autorun'
+
+class BasicCalculatorIITest < ::Minitest::Test
+  def test_default_one = assert_equal(7, calculate('3+2*2'))
+
+  def test_default_two = assert_equal(1, calculate(' 3/2 '))
+
+  def test_default_three = assert_equal(5, calculate(' 3+5 / 2 '))
+
+  def test_additional_one = assert_equal(1, calculate('2-1'))
+end