From c1046e1f7a3d7ab2ac74acdeb54561b58dce4715 Mon Sep 17 00:00:00 2001 From: Madeline Date: Fri, 21 May 2021 18:15:53 -0700 Subject: [PATCH 1/2] Added add method and fixed tests --- lib/tree.rb | 28 +++++++++++++++++++++++----- test/tree_test.rb | 22 +++++++++++----------- 2 files changed, 34 insertions(+), 16 deletions(-) diff --git a/lib/tree.rb b/lib/tree.rb index c0d4b51..85cb4a4 100644 --- a/lib/tree.rb +++ b/lib/tree.rb @@ -16,14 +16,32 @@ def initialize @root = nil end - # Time Complexity: - # Space Complexity: + # Time Complexity: + # Space Complexity: def add(key, value) - raise NotImplementedError + new_node = TreeNode.new(key, value) + + if root.nil? + @root = new_node + else + add_helper(@root, new_node) + end end - # Time Complexity: - # Space Complexity: + def add_helper(current, new_node) + return new_node if current.nil? + + if new_node.value <= current.value + current.left = add_helper(current.left, new_node) + else + current.right > add_helper(current.right, new_node) + end + + return current + end + + # Time Complexity: + # Space Complexity: def find(key) raise NotImplementedError end diff --git a/test/tree_test.rb b/test/tree_test.rb index 60f5981..21d1b41 100644 --- a/test/tree_test.rb +++ b/test/tree_test.rb @@ -91,7 +91,7 @@ it "will return 1 for a tree of height 1" do my_tree = Tree.new - my_tree.add(100) + my_tree.add(100, 1) expect(my_tree.height).must_equal 1 end @@ -102,11 +102,11 @@ it "will report the height for unbalanced trees" do my_tree = Tree.new - my_tree.add(100) - my_tree.add(110) - my_tree.add(120) - my_tree.add(130) - my_tree.add(140) + my_tree.add(100, 1) + my_tree.add(110, 1) + my_tree.add(120, 1) + my_tree.add(130, 1) + my_tree.add(140, 1) expect(my_tree.height).must_equal 5 @@ -114,11 +114,11 @@ my_tree = Tree.new - my_tree.add(100) - my_tree.add(90) - my_tree.add(80) - my_tree.add(70) - my_tree.add(60) + my_tree.add(100, 1) + my_tree.add(90, 1) + my_tree.add(80, 1) + my_tree.add(70, 1) + my_tree.add(60, 1) expect(my_tree.height).must_equal 5 end From 72fc6d6b065d49311d525b7edf167507d862d273 Mon Sep 17 00:00:00 2001 From: Madeline Date: Fri, 23 Jul 2021 14:29:26 -0400 Subject: [PATCH 2/2] Finished required methods --- lib/tree.rb | 86 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 66 insertions(+), 20 deletions(-) diff --git a/lib/tree.rb b/lib/tree.rb index 85cb4a4..dec81dc 100644 --- a/lib/tree.rb +++ b/lib/tree.rb @@ -16,12 +16,12 @@ def initialize @root = nil end - # Time Complexity: - # Space Complexity: + # Time Complexity: O(log n) + # Space Complexity: O(n) def add(key, value) new_node = TreeNode.new(key, value) - if root.nil? + if @root.nil? @root = new_node else add_helper(@root, new_node) @@ -31,43 +31,89 @@ def add(key, value) def add_helper(current, new_node) return new_node if current.nil? - if new_node.value <= current.value + if new_node.key <= current.key current.left = add_helper(current.left, new_node) else - current.right > add_helper(current.right, new_node) + current.right = add_helper(current.right, new_node) end return current end - # Time Complexity: - # Space Complexity: + # Time Complexity: O(log n) + # Space Complexity: O(log n) def find(key) - raise NotImplementedError + find_helper(key, @root) end - # Time Complexity: - # Space Complexity: + def find_helper(key, current) + return nil if current.nil? + + if current.key == key + return current.value + elsif current.key > key + find_helper(key, current.left) + elsif current.key < key + find_helper(key, current.right) + end + end + + # Time Complexity: O(n) + # Space Complexity: O(n) def inorder - raise NotImplementedError + inorder_helper(@root, []) end - # Time Complexity: - # Space Complexity: + def inorder_helper(current, values) + return values if current.nil? + + inorder_helper(current.left, values) + values << { key: current.key, value: current.value } + inorder_helper(current.right, values) + end + + # Time Complexity: O(n) + # Space Complexity: O(n) def preorder - raise NotImplementedError + return preorder_helper(@root, []) end - # Time Complexity: - # Space Complexity: + def preorder_helper(current, values) + return values if current.nil? + + values << { key: current.key, value: current.value } + preorder_helper(current.left, values) + preorder_helper(current.right, values) + end + + # Time Complexity: O(n) + # Space Complexity: O(n) def postorder - raise NotImplementedError + return postorder_helper(@root, []) end - # Time Complexity: - # Space Complexity: + def postorder_helper(current, values) + return values if current.nil? + + postorder_helper(current.left, values) + postorder_helper(current.right, values) + values << { key: current.key, value: current.value } + end + + # Time Complexity: O(n) + # Space Complexity: O(n) def height - raise NotImplementedError + return height_helper(@root) + end + + def height_helper(current) + return 0 if current.nil? + + if current + left_height = 1 + height_helper(current.left) + right_height = 1 + height_helper(current.right) + return left_height > right_height ? left_height : right_height + end end # Optional Method