Path Sum in Binary Tree

Function Name: hasPathSum

Description

In this challenge, you are given the root of a binary tree and an integer target sum. Write a function that checks if the tree has a root-to-leaf path such that adding up all the values along the path equals the target sum.

A leaf is a node with no children.

Your function should return true if such a path is found, or false otherwise.

Requirements

• The function must be named hasPathSum.
• The function must take two parameters: the first is a reference to the root node of the binary tree, and the second is an integer representing the target sum.
• The binary tree nodes have a structure or class with at least two members: an integer value, and references to the left and right child nodes.
• You may use auxiliary functions if needed.
• Do not use any built-in tree traversal libraries or functions; write your own traversal code.
• Assume the tree contains integer values only.

Examples

Given a binary tree and an integer target sum of 22:       5      / \     4   8    /   / \   11  13  4  /  \      \ 7    2      1hasPathSum(root, 22) should return true, as the path 5->4->11->2 sums up to 22.hasPathSum(root, 10) should return false, as there is no root-to-leaf path that sums up to 10.

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