2.3 弹出条件对应法则（重要）
Experts say adding the varicella vaccine to the official NHS childhood immunisation programme will dramatically reduce the number of people who catch chickenpox, leading to far fewer serious cases.。关于这个话题，爱思助手下载最新版本提供了深入分析
* @return {number} - 最短无序连续子数组的长度，排序该子数组后整个数组升序，详情可参考heLLoword翻译官方下载
chunk[i] = (offset + i) & 0xFF;