Path Sum

 1 /**

 2  * Definition for binary tree

 3  * public class TreeNode {

 4  *     int val;

 5  *     TreeNode left;

 6  *     TreeNode right;

 7  *     TreeNode(int x) { val = x; }

 8  * }

 9  */

10 public class Solution {

11     public boolean hasPathSum(TreeNode root, int sum) {

12         if(root==null) return false;

13         if(root.val==sum&&root.left==null&&root.right==null)return true;

14         if(root.left!=null)

15         {

16             if(hasPathSum(root.left,sum-root.val))

17             return true;

18         }

19         if(root.right!=null)

20         {

21              if(hasPathSum(root.right,sum-root.val))

22             return true;

23         }    

24         return false;

25             

26     }

27 }