Q112 Path Sum
Q112 Path Sum

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.

For 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.

robertzm/algotest