LeetCode112 Path Sum

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

For example:
Given the below binary tree and sum = 22,

              5
             /             4   8
           /   /           11  13  4
         /  \              7    2      1

return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.

/**
 * 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.left==null&&root.right==null){
             if(root.val==sum){
                 return true;
             }else{
                 return false;
             }

         }
        return (hasPathSum(root.left,(sum-root.val))||hasPathSum(root.right,(sum-root.val)));
    }
}