ruby/binary-search-tree: download exercise

ruby/binary-search-tree/.exercism/config.json

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+{
+  "authors": [
+    "vosechu"
+  ],
+  "contributors": [
+    "budmc29",
+    "cadwallion",
+    "dkinzer",
+    "hilary",
+    "iHiD",
+    "Insti",
+    "kotp",
+    "kytrinyx",
+    "pendletons",
+    "remcopeereboom",
+    "Ryan1729",
+    "tryantwit"
+  ],
+  "files": {
+    "solution": [
+      "binary_search_tree.rb"
+    ],
+    "test": [
+      "binary_search_tree_test.rb"
+    ],
+    "example": [
+      ".meta/example.rb"
+    ]
+  },
+  "blurb": "Insert and search for numbers in a binary tree.",
+  "source": "Josh Cheek",
+  "source_url": "https://twitter.com/josh_cheek"
+}

ruby/binary-search-tree/.exercism/metadata.json

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+{"track":"ruby","exercise":"binary-search-tree","id":"fd41235f072844e28632df5ffead0037","url":"https://exercism.org/tracks/ruby/exercises/binary-search-tree","handle":"vpayno","is_requester":true,"auto_approve":false}

ruby/binary-search-tree/HELP.md

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+# Help
+
+## Running the tests
+
+For running the tests provided, you will need the Minitest gem. Open a
+terminal window and run the following command to install minitest:
+
+```
+gem install minitest
+```
+
+
+Run the tests from the exercise directory using the following command:
+
+```
+ruby <snake-case-exercise>_test.rb
+```
+
+Please replace `<snake-case-exercise>` with your exercise name in snake_case.
+
+## Color output
+
+You can `require 'minitest/pride'` or run the following command to get colored output:
+
+```
+ruby -r minitest/pride <snake-case-exercise>_test.rb
+```
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit binary_search_tree.rb` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Ruby track's documentation](https://exercism.org/docs/tracks/ruby)
+- The [Ruby track's programming category on the forum](https://forum.exercism.org/c/programming/ruby)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+To get help if you're having trouble, you can use one of the following resources:
+
+- [Ruby Documentation](http://ruby-doc.org/)
+- [StackOverflow](http://stackoverflow.com/questions/tagged/ruby)
+- [/r/ruby](https://www.reddit.com/r/ruby) is the Ruby subreddit.

ruby/binary-search-tree/README.md

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+# Binary Search Tree
+
+Welcome to Binary Search Tree on Exercism's Ruby Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Insert and search for numbers in a binary tree.
+
+When we need to represent sorted data, an array does not make a good data structure.
+
+Say we have the array `[1, 3, 4, 5]`, and we add 2 to it so it becomes `[1, 3, 4, 5, 2]`.
+Now we must sort the entire array again!
+We can improve on this by realizing that we only need to make space for the new item `[1, nil, 3, 4, 5]`, and then adding the item in the space we added.
+But this still requires us to shift many elements down by one.
+
+Binary Search Trees, however, can operate on sorted data much more efficiently.
+
+A binary search tree consists of a series of connected nodes.
+Each node contains a piece of data (e.g. the number 3), a variable named `left`, and a variable named `right`.
+The `left` and `right` variables point at `nil`, or other nodes.
+Since these other nodes in turn have other nodes beneath them, we say that the left and right variables are pointing at subtrees.
+All data in the left subtree is less than or equal to the current node's data, and all data in the right subtree is greater than the current node's data.
+
+For example, if we had a node containing the data 4, and we added the data 2, our tree would look like this:
+
+      4
+     /
+    2
+
+If we then added 6, it would look like this:
+
+      4
+     / \
+    2   6
+
+If we then added 3, it would look like this
+
+       4
+     /   \
+    2     6
+     \
+      3
+
+And if we then added 1, 5, and 7, it would look like this
+
+          4
+        /   \
+       /     \
+      2       6
+     / \     / \
+    1   3   5   7
+
+## Source
+
+### Created by
+
+- @vosechu
+
+### Contributed to by
+
+- @budmc29
+- @cadwallion
+- @dkinzer
+- @hilary
+- @iHiD
+- @Insti
+- @kotp
+- @kytrinyx
+- @pendletons
+- @remcopeereboom
+- @Ryan1729
+- @tryantwit
+
+### Based on
+
+Josh Cheek - https://twitter.com/josh_cheek

ruby/binary-search-tree/binary_search_tree.rb

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+=begin
+Write your code for the 'Binary Search Tree' exercise in this file. Make the tests in
+`binary_search_tree_test.rb` pass.
+
+To get started with TDD, see the `README.md` file in your
+`ruby/binary-search-tree` directory.
+=end

ruby/binary-search-tree/binary_search_tree_test.rb

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+require 'minitest/autorun'
+require_relative 'binary_search_tree'
+
+class BstTest < Minitest::Test
+  def test_data_is_retained
+    assert_equal 4, Bst.new(4).data
+  end
+
+  def test_inserting_less
+    skip
+    four = Bst.new 4
+    four.insert 2
+    assert_equal 4, four.data
+    assert_equal 2, four.left.data
+  end
+
+  def test_inserting_same
+    skip
+    four = Bst.new 4
+    four.insert 4
+    assert_equal 4, four.data
+    assert_equal 4, four.left.data
+  end
+
+  def test_inserting_right
+    skip
+    four = Bst.new 4
+    four.insert 5
+    assert_equal 4, four.data
+    assert_equal 5, four.right.data
+  end
+
+  def test_complex_tree
+    skip
+    four = Bst.new 4
+    four.insert 2
+    four.insert 6
+    four.insert 1
+    four.insert 3
+    four.insert 7
+    four.insert 5
+    assert_equal 4, four.data
+    assert_equal 2, four.left.data
+    assert_equal 1, four.left.left.data
+    assert_equal 3, four.left.right.data
+    assert_equal 6, four.right.data
+    assert_equal 5, four.right.left.data
+    assert_equal 7, four.right.right.data
+  end
+
+  def record_all_data(bst)
+    all_data = []
+    bst.each { |data| all_data << data }
+    all_data
+  end
+
+  def test_iterating_one_element
+    skip
+    assert_equal [4], record_all_data(Bst.new(4))
+  end
+
+  def test_iterating_over_smaller_element
+    skip
+    four = Bst.new 4
+    four.insert 2
+    assert_equal [2, 4], record_all_data(four)
+  end
+
+  def test_iterating_over_larger_element
+    skip
+    four = Bst.new 4
+    four.insert 5
+    assert_equal [4, 5], record_all_data(four)
+  end
+
+  def test_iterating_over_complex_tree
+    skip
+    four = Bst.new 4
+    four.insert 2
+    four.insert 1
+    four.insert 3
+    four.insert 6
+    four.insert 7
+    four.insert 5
+    assert_equal [1, 2, 3, 4, 5, 6, 7], record_all_data(four)
+  end
+
+  def test_each_returns_enumerator_if_no_block
+    skip
+
+    tree = Bst.new 4
+    [2, 1, 3, 6, 7, 5].each { |x| tree.insert x }
+    each_enumerator = tree.each
+
+    assert_kind_of Enumerator, each_enumerator
+
+    (1..7).each { |x| assert_equal(x, each_enumerator.next) }
+
+    assert_raises(StopIteration) { each_enumerator.next }
+  end
+end