1
var hasPathSum = function (root, targetSum) {
2
  return DFS(root, 0, targetSum);
3
};
4

5
const DFS = (curr, currentSum, targetSum) => {
6
  if (!curr) return false;
7

8
  currentSum += curr.val;
9

10
  if (!curr.left && !curr.right) return currentSum === targetSum;
11

12
  return (
13
    DFS(curr.left, currentSum, targetSum) ||
14
    DFS(curr.right, currentSum, targetSum)
15
  );
16
};