/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public boolean hasPathSum(TreeNode root, int sum) { if(root == null) return false; if(root.val == sum && root.left==null && root.right == null) return true; return hasPathSum(root.left,sum-root.val) || hasPathSum(root.right,sum-root.val); } }