feat: Add Ruby code - chapter "Hashing" (#1276)

* feat: add ruby code - chapter hashing

* feat: add ruby code blocks - chapter hashing

* fix: comments

codes/ruby/chapter_hashing/array_hash_map.rb

@@ -0,0 +1,121 @@
+=begin
+File: array_hash_map.rb
+Created Time: 2024-04-13
+Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
+=end
+
+### 键值对 ###
+class Pair
+  attr_accessor :key, :val
+
+  def initialize(key, val)
+    @key = key
+    @val = val
+  end
+end
+
+### 基于数组实现的哈希表 ###
+class ArrayHashMap
+  ### 构造方法 ###
+  def initialize
+    # 初始化数组，包含 100 个桶
+    @buckets = Array.new(100)
+  end
+
+  ### 哈希函数 ###
+  def hash_func(key)
+    index = key % 100
+  end
+
+  ### 查询操作 ###
+  def get(key)
+    index = hash_func(key)
+    pair = @buckets[index]
+
+    return if pair.nil?
+    pair.val
+  end
+
+  ### 添加操作 ###
+  def put(key, val)
+    pair = Pair.new(key, val)
+    index = hash_func(key)
+    @buckets[index] = pair
+  end
+
+  ### 删除操作 ###
+  def remove(key)
+    index = hash_func(key)
+    # 置为 nil ，代表删除
+    @buckets[index] = nil
+  end
+
+  ### 获取所有键值对 ###
+  def entry_set
+    result = []
+    @buckets.each { |pair| result << pair unless pair.nil? }
+    result
+  end
+
+  ### 获取所有键 ###
+  def key_set
+    result = []
+    @buckets.each { |pair| result << pair.key unless pair.nil? }
+    result
+  end
+
+  ### 获取所有值 ###
+  def value_set
+    result = []
+    @buckets.each { |pair| result << pair.val unless pair.nil? }
+    result
+  end
+
+  ### 打印哈希表 ###
+  def print
+    @buckets.each { |pair| puts "#{pair.key} -> #{pair.val}" unless pair.nil? }
+  end
+end
+
+### Driver Code ###
+if __FILE__ == $0
+  # 初始化哈希表
+  hmap = ArrayHashMap.new
+
+  # 添加操作
+  # 在哈希表中添加键值对 (key, value)
+  hmap.put(12836, "小哈")
+  hmap.put(15937, "小啰")
+  hmap.put(16750, "小算")
+  hmap.put(13276, "小法")
+  hmap.put(10583, "小鸭")
+  puts "\n添加完成后，哈希表为\nKey -> Value"
+  hmap.print
+
+  # 查询操作
+  # 向哈希表中输入键 key , 得到值 value
+  name = hmap.get(15937)
+  puts "\n输入学号 15937 ，查询到姓名 #{name}"
+
+  # 删除操作
+  # 在哈希表中删除值对 (key, value)
+  hmap.remove(10583)
+  puts "\n删除 10583 后，哈希表为\nKey -> Value"
+  hmap.print
+
+  # 遍历哈希表
+  puts "\n遍历键值对 Key->Value"
+  for pair in hmap.entry_set
+    puts "#{pair.key} -> #{pair.val}"
+  end
+
+  puts "\n单独篇遍历键 Key"
+  for key in hmap.key_set
+    puts key
+  end
+
+  puts "\n单独遍历值 Value"
+  for val in hmap.value_set
+    puts val
+  end
+end