feat: Add Ruby code - chapter "Searching" (#1262)

* create RUBY searching files & finish two_sum.rb

* finish linear_search.rb

* finish hashing_search.rb

* finish binary_search.rb

* finish binary_search_insertion.rb

* finish binary_search_edge.rb

* fix: change 'or' to '||'

* fix: Adjust the code style(ruby searching)

* fix: repair file name

* fix: Adjust the output format

* fix: fix 0...nums.length & delete useless require & change into __FILE__==0 block

codes/ruby/chapter_searching/two_sum.rb

@@ -0,0 +1,46 @@
+=begin
+File: two_sum.rb
+Created Time: 2024-04-09
+Author: Blue Bean (lonnnnnnner@gmail.com)
+=end
+
+### 方法一：暴力枚举 ###
+def two_sum_brute_force(nums, target)
+  # 两层循环，时间复杂度为 O(n^2)
+  for i in 0...(nums.length - 1)
+    for j in (i + 1)...nums.length
+      return [i, j] if nums[i] + nums[j] == target
+    end
+  end
+
+  []
+end
+
+### 方法二：辅助哈希表 ###
+def two_sum_hash_table(nums, target)
+  # 辅助哈希表，空间复杂度为 O(n)
+  dic = {}
+  # 单层循环，时间复杂度为 O(n)
+  for i in 0...nums.length
+    return [dic[target - nums[i]], i] if dic.has_key?(target - nums[i])
+
+    dic[nums[i]] = i
+  end
+
+  []
+end
+
+### Driver Code ###
+if __FILE__ == $0
+  # ======= Test Case =======
+  nums = [2, 7, 11, 15]
+  target = 13
+
+  # ====== Driver Code ======
+  # 方法一
+  res = two_sum_brute_force(nums, target)
+  puts "方法一 res = #{res}"
+  # 方法二
+  res = two_sum_hash_table(nums, target)
+  puts "方法二 res = #{res}"
+end