Time - Hannah T

lib/tree.rb

@@ -1,62 +1,141 @@
+require "pry"
+
 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
   attr_reader :root
+
   def initialize
     @root = nil
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity: O(Log n)
+  # Space Complexity: O(1)
   def add(key, value)
-    raise NotImplementedError
+    new_node = TreeNode.new(key, value)
+    if !@root
+      @root = new_node
+      return
+    end
+    current = @root
+    while current != nil
+      if key < current.key
+        if current.left
+          current = current.left
+        else
+          current.left = new_node
+          return
+        end
+      else
+        if current.right
+          current = current.right
+        else
+          current.right = new_node
+          return
+        end
+      end
+    end
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity: O(Log n)
+  # Space Complexity: O(1)
   def find(key)
-    raise NotImplementedError
+    current = @root
+    while current != nil
+      if key == current.key
+        return current.value
+      elsif key < current.key
+        current = current.left
+      else
+        current = current.right
+      end
+    end
+    return nil
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity: O(Log n)
+  # Space Complexity: O(n)
   def inorder
-    raise NotImplementedError
+    ary = []
+
+    def innerfunc(node, ary)
+      return if node.nil?
+      innerfunc(node.left, ary)
+      ary << { :key => node.key, :value => node.value }
+      innerfunc(node.right, ary)
+    end
+
+    innerfunc(@root, ary)
+    return ary
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity: O(Log n)
+  # Space Complexity: O(n)
   def preorder
-    raise NotImplementedError
+    ary = []
+
+    def innerfunc(node, ary)
+      return if node.nil?
+      ary << { :key => node.key, :value => node.value }
+      innerfunc(node.left, ary)
+      innerfunc(node.right, ary)
+    end
+
+    innerfunc(@root, ary)
+    return ary
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity: O(Log n)
+  # Space Complexity: O(n)
+
   def postorder
-    raise NotImplementedError
+    ary = []
+    def innerfunc(node, ary)
+      return if node.nil?
+      innerfunc(node.left, ary)
+      innerfunc(node.right, ary)
+      ary << { :key => node.key, :value => node.value }
+    end
+
+    innerfunc(@root, ary)
+    return ary
   end
 
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity:
+  # Space Complexity:
   def height
-    raise NotImplementedError
+    def innerfunc(node)
+      return 0 if node.nil?
+      return 1 if !node.left && !node.right
+      return [innerfunc(node.left) + 1, innerfunc(node.right) + 1].max
+    end
+
+    return innerfunc(@root)
   end
 
   # Optional Method
-  # Time Complexity: 
-  # Space Complexity: 
+  # Time Complexity:
+  # Space Complexity:
   def bfs
-    raise NotImplementedError
+    q = [@root]
+    ary = []
+    while !q.empty?
+      current = q.pop
+      q << current.left if current.left
+      q << current.right if current.right
+      ary << { :key => current.key, :value => current.value }
+    end
+    return ary
   end
 
   # Useful for printing