Merge pull request #676 from fartem/55_Jump_Game

2024-07-17 v. 6.1.9: added "55. Jump Game"

Author: fartem

README.md

@@ -484,3 +484,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 49. Group Anagrams                                          | [Link](https://leetcode.com/problems/group-anagrams/)                                          | [Link](./lib/medium/49_group_anagrams.rb)                                          |
 | 53. Maximum Subarray                                        | [Link](https://leetcode.com/problems/maximum-subarray/)                                        | [Link](./lib/medium/53_maximum_subarray.rb)                                        |
 | 54. Spiral Matrix                                           | [Link](https://leetcode.com/problems/spiral-matrix/)                                           | [Link](./lib/medium/54_spiral_matrix.rb)                                           |
+| 55. Jump Game                                               | [Link](https://leetcode.com/problems/jump-game/)                                               | [Link](./lib/medium/55_jump_game.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 = '6.1.8'
+  s.version = '6.1.9'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/55_jump_game.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/jump-game/
+# @param {Integer[]} nums
+# @return {Boolean}
+def can_jump(nums)
+  reachable = 0
+  nums.each_with_index do |n, i|
+    return false if i > reachable
+
+    reachable = [(n + i), reachable].max
+  end
+
+  reachable >= nums.length - 1
+end

test/medium/test_55_jump_game.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/55_jump_game'
+require 'minitest/autorun'
+
+class JumpGameTest < ::Minitest::Test
+  def test_default
+    assert(can_jump([2, 3, 1, 1, 4]))
+    assert(!can_jump([3, 2, 1, 0, 4]))
+  end
+end