1. 选择步长序列（如: n/2, n/4, ..., 1）
The tests used in standards for evaluating smoke alarms were developed back in the 1980s. However, despite changes in building materials since then, smoke alarms remain reliable, says Chagger: "They still respond to all the main fires we get today."，这一点在safew官方版本下载中也有详细论述
And check the next blog post about a simplified deprecation API built on top of BPatterns:。关于这个话题，WPS官方版本下载提供了深入分析
let prevFleetTime = -Infinity; // 上一个独立车队的到达时间（初始负无穷，保证第一个车被统计）