Path Sum

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean hasPathSum(TreeNode root, int sum) {
        // Note: The Solution object is instantiated only once and is reused by each test case.
        if(root == null) return false;
        int cal = 0;
        if(helpler(root, cal, sum))
            return true;
        else
            return false;
    }
    private boolean helpler(TreeNode root, int cal, int sum)
    {
        cal+=root.val;
        if(root.left==null && root.right==null)
        {
            if(cal == sum)
                return true;
            else
                return false;
        }
        if(root.left != null && root.right != null)  
            return helpler(root.left, cal, sum) | helpler(root.right, cal, sum);
        else if(root.left != null)
            return helpler(root.left, cal, sum);
        else
            return helpler(root.right, cal, sum);
    }
}