Leetcode112. 路径总和

题目传送：​​https://leetcode.cn/problems/path-sum/submissions/​​

运行效率

代码如下：

public boolean hasPathSum(TreeNode root, int targetSum) {
        //处理边界情况
        if(root==null){
            return false;
        }
        //如果是叶子节点
        if(root.left==null&&root.right==null){
            return root.val==targetSum;
        }
        //如果不是叶子节点
        boolean a = hasPathSum(root.left, targetSum - root.val);
        boolean b = hasPathSum(root.right, targetSum - root.val);
        return  a||b;
    }