Merge pull request kelvins#323 from mfornaciari/add-binary-tree-in-ruby

Add binary tree in Ruby

Author: kelvins

README.md

@@ -1718,8 +1718,8 @@ In order to achieve greater coverage and encourage more people to contribute to
                 </a>
             </td>
             <td> <!-- Ruby -->
-                <a href="./CONTRIBUTING.md">
-                    <img align="center" height="25" src="./logos/github.svg" />
+                <a href="./src/ruby/binary_tree.rb">
+                    <img align="center" height="25" src="./logos/ruby.svg" />
                 </a>
             </td>
             <td> <!-- JavaScript -->

src/ruby/binary_tree.rb

@@ -0,0 +1,67 @@
+# frozen_string_literal: true
+
+require "test/unit/assertions"
+include Test::Unit::Assertions
+
+class BinaryTree
+  attr_accessor :value
+  attr_writer :left, :right
+
+  def left
+    @left ||= BinaryTree.new
+  end
+
+  def right
+    @right ||= BinaryTree.new
+  end
+
+  def search(received_value)
+    return value if value == received_value || value.nil?
+
+    if received_value < value
+      left.search(received_value)
+    else
+      right.search(received_value)
+    end
+  end
+
+  def insert(received_value)
+    return @value = received_value if value.nil?
+    return left.insert(received_value) if received_value <= value
+
+    right.insert(received_value)
+  end
+
+  def to_a
+    return [] if value.nil?
+
+    left.to_a + [value] + right.to_a
+  end
+end
+
+tree = BinaryTree.new
+
+tree.insert(42)
+tree.insert(43)
+tree.insert(44)
+
+assert_equal(42, tree.search(42))
+assert_equal(43, tree.search(43))
+assert_equal(44, tree.search(44))
+assert_equal(nil, tree.search(45))
+
+tree = BinaryTree.new
+
+assert_equal([], tree.to_a)
+
+tree.insert(42)
+
+assert_equal([42], tree.to_a)
+
+tree.insert(43)
+
+assert_equal([42, 43], tree.to_a)
+
+tree.insert(41)
+
+assert_equal([41, 42, 43], tree.to_a)