题目介绍

题解

java">class Solution {public boolean hasPathSum(TreeNode root, int targetSum) {// 只在最开始的时候判断树是否为空if (root == null) {return false;}targetSum -= root.val;if (root.left == null && root.right == null) { // root 是叶子节点return targetSum == 0;}return hasPathSum(root.left, targetSum) || hasPathSum(root.right, targetSum);}
}