From 166cbf8cb05c6755f4bd87b290a4225876d9a377 Mon Sep 17 00:00:00 2001
From: fartem <jaman.smlnsk@gmail.com>
Date: Wed, 12 Mar 2025 09:18:37 +0300
Subject: [PATCH] 2025-03-12 v. 8.9.3: added "2023. Number of Pairs of Strings
With Concatenation Equal to Target"
---
README.md | 1 +
leetcode-ruby.gemspec | 2 +-
...ings_with_concatenation_equal_to_target.rb | 25 +++++++++++++
...ings_with_concatenation_equal_to_target.rb | 37 +++++++++++++++++++
4 files changed, 64 insertions(+), 1 deletion(-)
create mode 100644 lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
create mode 100644 test/medium/test_2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
diff --git a/README.md b/README.md
index 50cb21fa..03d53340 100644
--- a/README.md
+++ b/README.md
@@ -726,6 +726,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
| 1985. Find the Kth Largest Integer in the Array | [Link](https://leetcode.com/problems/find-the-kth-largest-integer-in-the-array/) | [Link](./lib/medium/1985_find_the_kth_largest_integer_in_the_array.rb) | [Link](./test/medium/test_1985_find_the_kth_largest_integer_in_the_array.rb) |
| 1996. The Number of Weak Characters in the Game | [Link](https://leetcode.com/problems/the-number-of-weak-characters-in-the-game/) | [Link](./lib/medium/1996_the_number_of_weak_characters_in_the_game.rb) | [Link](./test/medium/test_1996_the_number_of_weak_characters_in_the_game.rb) |
| 2007. Find Original Array From Doubled Array | [Link](https://leetcode.com/problems/find-original-array-from-doubled-array/) | [Link](./lib/medium/2007_find_original_array_from_doubled_array.rb) | [Link](./test/medium/test_2007_find_original_array_from_doubled_array.rb) |
+| 2023. Number of Pairs of Strings With Concatenation Equal to Target | [Link](https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target/) | [Link](./lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb) | [Link](./test/medium/test_2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb) |
| 2116. Check if a Parentheses String Can Be Valid | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/) | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb) | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb) |
| 2425. Bitwise XOR of All Pairings | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/) | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb) | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb) |
| 2429. Minimize XOR | [Link](https://leetcode.com/problems/minimize-xor/) | [Link](./lib/medium/2429_minimize_xor.rb) | [Link](./test/medium/test_2429_minimize_xor.rb) |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 27dd03f7..a31f4302 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 = '8.9.2'
+ s.version = '8.9.3'
s.license = 'MIT'
s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
s.executable = 'leetcode-ruby'
diff --git a/lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb b/lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
new file mode 100644
index 00000000..2ae56b55
--- /dev/null
+++ b/lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/number-of-pairs-of-strings-with-concatenation-equal-to-target/
+# @param {String[]} nums
+# @param {String} target
+# @return {Integer}
+def num_of_pairs(nums, target)
+ count = 0
+ freq = ::Hash.new(0)
+
+ nums.each { |num| freq[num] += 1 }
+
+ nums.each do |s|
+ next unless target.start_with?(s)
+
+ remaining = target[s.size..]
+
+ next unless freq.key?(remaining)
+
+ count += freq[remaining]
+ count -= 1 if s == remaining
+ end
+
+ count
+end
diff --git a/test/medium/test_2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb b/test/medium/test_2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
new file mode 100644
index 00000000..93a2c31f
--- /dev/null
+++ b/test/medium/test_2023_number_of_pairs_of_strings_with_concatenation_equal_to_target.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/2023_number_of_pairs_of_strings_with_concatenation_equal_to_target'
+require 'minitest/autorun'
+
+class NumberOfPairsOfStringsWithConcatenationEqualToTargetTest < ::Minitest::Test
+ def test_default_one
+ assert_equal(
+ 4,
+ num_of_pairs(
+ %w[777 7 77 77],
+ '7777'
+ )
+ )
+ end
+
+ def test_default_two
+ assert_equal(
+ 2,
+ num_of_pairs(
+ %w[123 4 12 34],
+ '1234'
+ )
+ )
+ end
+
+ def test_default_three
+ assert_equal(
+ 6,
+ num_of_pairs(
+ %w[1 1 1],
+ '11'
+ )
+ )
+ end
+end