Add Ruby snippet for implementing a basic binary tree with in-order traversal

Author: ACR1209

snippets/ruby/data-structures/binary-tree.md

@@ -0,0 +1,42 @@
+---
+title: Binary Tree
+description: Implements a basic binary tree with in-order traversal.
+author: ACR1209
+tags: ruby,data structures,binary tree
+---
+
+```rb
+class TreeNode
+  attr_accessor :data, :left, :right
+
+  def initialize(data)
+      @data = data
+      @left = nil
+      @right = nil
+  end
+end
+
+class BinaryTree
+  attr_accessor :root
+
+  def initialize(root_data)
+      @root = TreeNode.new(root_data)
+  end
+
+  def in_order_traversal(node = @root, result = [])
+      return result unless node
+
+      in_order_traversal(node.left, result)
+      result << node.data
+      in_order_traversal(node.right, result)
+  end
+end
+
+# Usage:
+tree = BinaryTree.new(10)
+tree.root.left = TreeNode.new(5)
+tree.root.right = TreeNode.new(15)
+tree.root.left.left = TreeNode.new(3)
+
+print tree.in_order_traversal # Output: [3, 5, 10, 15]
+```