// problem link https://leetcode.com/problems/path-sum/
// time complexity O(n) // whatever the number of nodes are.
var hasPathSum = function(root, targetSum) {
const ans = [];
function goDFS(node, curruntSum) {
if(!node) return;
if(!node.left && !node.right) {
ans.push(node.val + curruntSum);
}
goDFS(node.left, curruntSum + node.val);
goDFS(node.right, curruntSum + node.val);
}
goDFS(root, 0);
return ans.includes(targetSum);
};