树中是否存在路径和为 sum leecode java

https://oj.leetcode.com/problems/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) {

        if(root==null) return false;

        if(root.left==null&&root.right==null)

        {

            if(sum==root.val) return true;

            

        }

        

        

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

        

        

    

        

    }

}