From 2d0b30822bb599e056316ef76149e3f81a1be1ce Mon Sep 17 00:00:00 2001 From: Diana Date: Tue, 25 Feb 2020 21:38:31 -0800 Subject: [PATCH 1/2] passing all tests, except for optional functions --- lib/tree.rb | 103 +++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 94 insertions(+), 9 deletions(-) diff --git a/lib/tree.rb b/lib/tree.rb index c0d4b51..cf0df9d 100644 --- a/lib/tree.rb +++ b/lib/tree.rb @@ -2,12 +2,12 @@ class TreeNode attr_reader :key, :value attr_accessor :left, :right - def initialize(key, val) + def initialize(key, val) @key = key @value = val @left = nil @right = nil - end + end end class Tree @@ -18,38 +18,123 @@ def initialize # Time Complexity: # Space Complexity: - def add(key, value) - raise NotImplementedError + # def add(key, value) + # if @root.nil? + # @root = TreeNode.new(key, value) + # else + # current = @root + + # while true + # if key < current.key + # if !current.left.nil? + # current = current.left + # else + # current.left = TreeNode.new(key, value) + # return + # end + # else + # if !current.right.nil? + # current = current.right + # else + # current.right = TreeNode.new(key, value) + # return + # end + # end + # end + # end + # end + + def add_helper(current_node, key, value) + return TreeNode.new(key, value) if current_node.nil? + + if key < current_node.key + current_node.left = add_helper(current_node.left, key, value) + else + current_node.right = add_helper(current_node.right, key, value) + end + + return current_node end + def add(key, value) + @root = add_helper(@root, key, value) + end # Time Complexity: # Space Complexity: def find(key) - raise NotImplementedError + current = @root + + return nil if current.nil? + + until current.key == key + if current.key > key + current = current.left + else + current = current.right + end + end + return current.value end + def inorder_helper(current_node, list) #l, n, r + return list if current_node.nil? + + inorder_helper(current_node.left, list) + list << { key: current_node.key, value: current_node.value} # root is getting pushed to the list + inorder_helper(current_node.right, list) + return list + end # Time Complexity: # Space Complexity: def inorder - raise NotImplementedError + return inorder_helper(@root, []) end + def preorder_helper(current_node, list) #n, l, r + return list if current_node.nil? + + list << {key: current_node.key, value: current_node.value} + preorder_helper(current_node.left, list) + preorder_helper(current_node.right, list) + return list + end # Time Complexity: # Space Complexity: def preorder - raise NotImplementedError + preorder_helper(@root, []) end + def postorder_helper(current_node, list) #l, r, n + return list if current_node.nil? + + postorder_helper(current_node.left, list) + postorder_helper(current_node.right, list) + list << {key: current_node.key, value: current_node.value} + return list + end # Time Complexity: # Space Complexity: def postorder - raise NotImplementedError + postorder_helper(@root, []) + end + + def height_helper(current_node) + return 0 if current_node.nil? + + left_depth = height_helper(current_node.left) + right_depth = height_helper(current_node.right) + + if left_depth > right_depth + return left_depth + 1 + else + return right_depth + 1 + end end # Time Complexity: # Space Complexity: def height - raise NotImplementedError + height_helper(@root) end # Optional Method From c3f136842d479c6e9714285e69e29ef0c82c20dc Mon Sep 17 00:00:00 2001 From: Diana Date: Tue, 25 Feb 2020 21:44:34 -0800 Subject: [PATCH 2/2] added time and space complexity --- lib/tree.rb | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/lib/tree.rb b/lib/tree.rb index cf0df9d..dd9fa71 100644 --- a/lib/tree.rb +++ b/lib/tree.rb @@ -16,8 +16,6 @@ def initialize @root = nil end - # Time Complexity: - # Space Complexity: # def add(key, value) # if @root.nil? # @root = TreeNode.new(key, value) @@ -56,11 +54,14 @@ def add_helper(current_node, key, value) return current_node end + # Time Complexity: O(n) + # Space Complexity: O(1) def add(key, value) @root = add_helper(@root, key, value) end - # Time Complexity: - # Space Complexity: + + # Time Complexity: O(logn) + # Space Complexity: O(1) def find(key) current = @root @@ -84,8 +85,9 @@ def inorder_helper(current_node, list) #l, n, r inorder_helper(current_node.right, list) return list end - # Time Complexity: - # Space Complexity: + + # Time Complexity: O(n) + # Space Complexity: O(n) n represents the number of nodes in a tree def inorder return inorder_helper(@root, []) end @@ -98,8 +100,9 @@ def preorder_helper(current_node, list) #n, l, r preorder_helper(current_node.right, list) return list end - # Time Complexity: - # Space Complexity: + + # Time Complexity: O(n) + # Space Complexity: O(n) def preorder preorder_helper(@root, []) end @@ -112,8 +115,9 @@ def postorder_helper(current_node, list) #l, r, n list << {key: current_node.key, value: current_node.value} return list end - # Time Complexity: - # Space Complexity: + + # Time Complexity: O(n) + # Space Complexity: O(n) def postorder postorder_helper(@root, []) end @@ -131,8 +135,8 @@ def height_helper(current_node) end end - # Time Complexity: - # Space Complexity: + # Time Complexity: O(n) + # Space Complexity: O(1) def height height_helper(@root) end