2024-07-03 v. 6.0.2: added "16. 3Sum Closest"

Author: fartem

README.md

@@ -467,3 +467,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 11. Container With Most Water                     | [Link](https://leetcode.com/problems/container-with-most-water/)                      | [Link](./lib/medium/11_container_with_most_water.rb)                     |
 | 12. Integer to Roman                              | [Link](https://leetcode.com/problems/integer-to-roman/)                               | [Link](./lib/medium/12_integer_to_roman.rb)                              |
 | 15. 3Sum                                          | [Link](https://leetcode.com/problems/3sum/)                                           | [Link](./lib/medium/15_3sum.rb)                                          |
+| 16. 3Sum Closest                                  | [Link](https://leetcode.com/problems/3sum-closest/)                                   | [Link](./lib/medium/16_3sum_closest.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 = '6.0.1'
+  s.version = '6.0.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/16_3sum_closest.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/3sum-closest/
+# @param {Integer[]} nums
+# @param {Integer} target
+# @return {Integer}
+def three_sum_closest(nums, target)
+  n = nums.length
+
+  return nums[0] + nums[1] + nums[2] if n == 3
+
+  nums.sort!
+  n = nums.length
+  max = nums[n - 1] + nums[n - 2] + nums[n - 3]
+
+  return max if target > max
+
+  min = ::Float::INFINITY
+  (0...(n - 2)).each do |i|
+    l = i + 1
+    r = n - 1
+
+    while l < r
+      curr = nums[i]
+      max = curr + nums[r - 1] + nums[r]
+
+      break if target - max > min.abs
+
+      min_sum = curr + nums[l] + nums[l + 1]
+
+      break if min_sum - target > min.abs
+
+      sum = curr + nums[l] + nums[r]
+
+      return sum if sum == target
+
+      diff = sum - target
+      min = diff if diff.abs < min.abs
+
+      r -= 1 if diff.positive?
+      l += 1 if diff.negative?
+    end
+  end
+
+  target + min
+end

test/medium/test_16_3sum_closest.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/16_3sum_closest'
+require 'minitest/autorun'
+
+class ThreeSumClosestTest < ::Minitest::Test
+  def test_default
+    assert_equal(2, three_sum_closest([-1, 2, 1, -4], 1))
+    assert_equal(0, three_sum_closest([0, 0, 0], 1))
+  end
+end