/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {


    public boolean checkTree(TreeNode node, int sum, int currentSum){

        // ako e leafnode
        if(node.left == null && node.right == null && sum == currentSum + node.val){
            return true;
        }


        if(node == null){
            return false;
        }


        // 2 deca
        if(node.left != null && node.right != null){
            return checkTree(node.left, sum,currentSum + node.val) || checkTree(node.right, sum , currentSum + node.val);
        }

        // levo dete
        if(node.left != null){
            return checkTree(node.left, sum, currentSum + node.val);
        }


        // desno dete
        if(node.right != null){
            return checkTree(node.right, sum, currentSum + node.val);
        }

        return false;
    }


    public boolean hasPathSum(TreeNode root, int sum) {

        if(root == null){
            return false;
        }

        if(checkTree(root,sum,0) == true){
            return true;
        }
        return false;

    }
}