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 }