Given the root node of a binary tree and a sum, write a program to determine if there exists a path in the tree from root-to-leaf such that the sum of all the values along the path equals the given sum.

Problem Note

• A leaf is a node with no children.

Example 1

Input: Given the below binary tree and sum = 22
      6
     / \
    4   8
   /   / \
  10  14  3
 /  \      \
8    2      1
Output: 1
Explanation: There exist a root-to-leaf path 6->4->10->2 which sum is 22 so output is true i.e. 1