Find left most node on a binary tree problem.

Author: deepakhb2

Interview-Questions/count_max_sub_arr.rb

@@ -21,7 +21,6 @@ def count_subarrays(arr)
       end
     end
     j = i-1
-    p i
     while(j >= 0)
       if(arr[i] > arr[j])
         count += 1

Interview-Questions/left_most_node.rb

@@ -0,0 +1,92 @@
+=begin
+Signature
+int visibleNodes(Node root) {
+Input
+The root node of a tree, where the number of nodes is between 1 and 1000, and the value of each node is between 0 and 10,000,000,000
+Output
+An int representing the number of visible nodes.
+Example
+            8  <------ root
+           / \
+         3    10
+        / \     \
+       1   6     14
+          / \    /
+         4   7  13            
+output = 4
+=end
+
+class Node
+  attr_reader :value
+  attr_accessor :left, :right
+  
+  def initialize(value)
+    @value = value
+    @left = nil
+    @right = nil
+  end
+end
+
+class BinaryTree
+  attr_reader :root
+  
+  def initialize
+    @root = nil
+  end
+  
+  def insert(value)
+    new_node = Node.new(value)
+    unless @root
+      @root = new_node
+    else
+      temp_node = @root
+      while(temp_node)
+        if(temp_node.value > value)
+          unless(temp_node.left)
+            temp_node.left = new_node
+            return
+          end
+          temp_node = temp_node.left
+        else
+          unless(temp_node.right)
+            temp_node.right = new_node
+            return
+          end
+          temp_node = temp_node.right
+        end
+      end
+    end
+  end
+end
+
+
+def visible_node(root, left_most_node = {}, level=0)
+  if(level == 0)
+    left_most_node[level] = root.value
+  end
+  return left_most_node[level-1] unless root
+  level = level+1
+  unless(left_most_node[level])
+      if(root.left)
+        left_most_node[level] = root.left.value
+      elsif(root.right)
+        left_most_node[level] = root.right.value
+      end
+  end
+  visible_node(root.left, left_most_node, level)
+  visible_node(root.right, left_most_node, level)
+end
+
+bst = BinaryTree.new
+bst.insert(8)
+bst.insert(3)
+bst.insert(1)
+bst.insert(6)
+bst.insert(4)
+bst.insert(7)
+bst.insert(10)
+bst.insert(14)
+bst.insert(13)
+bst.insert(15)
+bst.insert(16)
+p visible_node(bst.root)