Given a binary tree and a sum, determine if the tree has a root-to- leaf path such that adding up all the values along the path equals the given sum. Note: A leaf is a node with no children. Example: Given the below binary tree and sum = 22, 5 4 8 11 13 4 7 2 1 return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22 | Input format: Line 1: Preorder serialization of a binary tree. (e.g. 5 4 11 7 null 3 10 4 1 1 Line 2: Sum (e.g. 22) Open in Window