输入：num = "1432219", k = 3
Think about the user experience difference. In traditional search, someone sees your site listed among ten results and must decide whether to click based on a title and two-line description. In AI search, someone reads an answer that includes information from your content, sees your site cited as the source, and arrives at your page already understanding its value and relevance. The qualification happens before the click, resulting in higher-quality traffic with better engagement metrics.
，这一点在safew官方版本下载中也有详细论述
arr.push(p.val); // 存储节点值而非节点本身，简化后续操作
Historic England