[LeetCode]112. Path Sum

https://leetcode.com/problems/path-sum/

求是否存在根节点到叶子节点的和为sum

如果当前位置为空就返回false，如果当前为叶子节点且值为sum，返回true，否则继续遍历

public class Solution { public boolean hasPathSum(TreeNode root, int sum) { if (root == null) { return false; } if (root.left == null && root.right == null && root.val == sum) { return true; } return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val); } }