feat: add ruby codes - chapter tree (#1288)

codes/ruby/chapter_tree/binary_tree.rb

@@ -0,0 +1,38 @@
+=begin
+File: binary_tree.rb
+Created Time: 2024-04-18
+Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
+=end
+
+require_relative '../utils/tree_node'
+require_relative '../utils/print_util'
+
+### Driver Code ###
+if __FILE__ == $0
+  # 初始化二叉树
+  # 初始化节点
+  n1 = TreeNode.new(1)
+  n2 = TreeNode.new(2)
+  n3 = TreeNode.new(3)
+  n4 = TreeNode.new(4)
+  n5 = TreeNode.new(5)
+  # 构建节点之间的引用（指针）
+  n1.left = n2
+  n1.right = n3
+  n2.left = n4
+  n2.right = n5
+  puts "\n初始化二叉树\n\n"
+  print_tree(n1)
+
+  # 插入与删除节点
+  _p = TreeNode.new(0)
+  # 在 n1 -> n2 中间插入节点 _p
+  n1.left = _p
+  _p.left = n2
+  puts "\n插入节点 _p 后\n\n"
+  print_tree(n1)
+  # 删除节点
+  n1.left = n2
+  puts "\n删除节点 _p 后\n\n"
+  print_tree(n1)
+end